Resiliency in a cloud-based storage system

ABSTRACT

Providing highly available application-specific storage by a cloud-based storage system, including: detecting that a component within a cloud-based storage system that supports an application has become unavailable; and selecting a replacement component within the cloud-based storage system to support the application, wherein at least a portion of a dataset associated with the application is stored as blocks within block storage resources in the cloud-based storage system and also stored as objects within object storage resources in the cloud-based storage system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 16/516,950, filed Jul. 19, 2019, which is a non-provisional application for patent entitled to a filing date and claiming the benefit of earlier-filed U.S. Provisional Patent Application Ser. No. 62/701,239, filed Jul. 20, 2018; U.S. Provisional Patent Application Ser. No. 62/731,295, filed Sep. 14, 2018; and U.S. Provisional Patent Application Ser. No. 62/875,947, filed Jul. 18, 2019.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A illustrates a first example system for data storage in accordance with some implementations.

FIG. 1B illustrates a second example system for data storage in accordance with some implementations.

FIG. 1C illustrates a third example system for data storage in accordance with some implementations.

FIG. 1D illustrates a fourth example system for data storage in accordance with some implementations.

FIG. 2A is a perspective view of a storage cluster with multiple storage nodes and internal storage coupled to each storage node to provide network attached storage, in accordance with some embodiments.

FIG. 2B is a block diagram showing an interconnect switch coupling multiple storage nodes in accordance with some embodiments.

FIG. 2C is a multiple level block diagram, showing contents of a storage node and contents of one of the non-volatile solid state storage units in accordance with some embodiments.

FIG. 2D shows a storage server environment, which uses embodiments of the storage nodes and storage units of some previous figures in accordance with some embodiments.

FIG. 2E is a blade hardware block diagram, showing a control plane, compute and storage planes, and authorities interacting with underlying physical resources, in accordance with some embodiments.

FIG. 2F depicts elasticity software layers in blades of a storage cluster, in accordance with some embodiments.

FIG. 2G depicts authorities and storage resources in blades of a storage cluster, in accordance with some embodiments.

FIG. 3A sets forth a diagram of a storage system that is coupled for data communications with a cloud services provider in accordance with some embodiments of the present disclosure.

FIG. 3B sets forth a diagram of a storage system in accordance with some embodiments of the present disclosure.

FIG. 3C sets forth an example of a cloud-based storage system in accordance with some embodiments of the present disclosure.

FIG. 3D sets forth an additional example of a cloud-based storage system in accordance with some embodiments of the present disclosure.

FIG. 3E illustrates an exemplary computing device that may be specifically configured to perform one or more of the processes described herein.

FIG. 4 sets forth a flow chart illustrating an example method of providing application-specific storage by a storage system in accordance with some embodiments of the present disclosure.

FIG. 5 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system in accordance with some embodiments of the present disclosure.

FIG. 6 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system in accordance with some embodiments of the present disclosure.

FIG. 7 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system in accordance with some embodiments of the present disclosure.

FIG. 8 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system in accordance with some embodiments of the present disclosure.

FIG. 9 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system in accordance with some embodiments of the present disclosure.

FIG. 10 sets forth a flow chart illustrating an example method of providing application-specific storage by a cloud-based storage system in accordance with some embodiments of the present disclosure.

FIG. 11 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a cloud-based storage system in accordance with some embodiments of the present disclosure.

FIG. 12 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a cloud-based storage system in accordance with some embodiments of the present disclosure.

FIG. 13 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a cloud-based storage system in accordance with some embodiments of the present disclosure.

FIG. 14 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a cloud-based storage system in accordance with some embodiments of the present disclosure.

FIG. 15 sets forth a graphical user interface (GUI′) for tuning storage according to some embodiments of the present disclosure.

FIG. 16 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a cloud-based storage system in accordance with some embodiments of the present disclosure.

DESCRIPTION OF EMBODIMENTS

Example methods, apparatus, and products for providing application-specific storage by a storage system in accordance with embodiments of the present disclosure are described with reference to the accompanying drawings, beginning with FIG. 1A. FIG. 1A illustrates an example system for data storage, in accordance with some implementations. System 100 (also referred to as “storage system” herein) includes numerous elements for purposes of illustration rather than limitation. It may be noted that system 100 may include the same, more, or fewer elements configured in the same or different manner in other implementations.

System 100 includes a number of computing devices 164A-B. Computing devices (also referred to as “client devices” herein) may be embodied, for example, a server in a data center, a workstation, a personal computer, a notebook, or the like. Computing devices 164A-B may be coupled for data communications to one or more storage arrays 102A-B through a storage area network (SAN′) 158 or a local area network (‘LAN’) 160.

The SAN 158 may be implemented with a variety of data communications fabrics, devices, and protocols. For example, the fabrics for SAN 158 may include Fibre Channel, Ethernet, Infiniband, Serial Attached Small Computer System Interface (′ SAS′), or the like. Data communications protocols for use with SAN 158 may include Advanced Technology Attachment (‘ATA’), Fibre Channel Protocol, Small Computer System Interface (‘SCSI’), Internet Small Computer System Interface (‘iSCSI’), HyperSCSI, Non-Volatile Memory Express (‘NVMe’) over Fabrics, or the like. It may be noted that SAN 158 is provided for illustration, rather than limitation. Other data communication couplings may be implemented between computing devices 164A-B and storage arrays 102A-B.

The LAN 160 may also be implemented with a variety of fabrics, devices, and protocols. For example, the fabrics for LAN 160 may include Ethernet (802.3), wireless (802.11), or the like. Data communication protocols for use in LAN 160 may include Transmission Control Protocol (‘TCP’), User Datagram Protocol (‘UDP’), Internet Protocol (‘IP’), HyperText Transfer Protocol (‘HTTP’), Wireless Access Protocol (‘WAP’), Handheld Device Transport Protocol (‘HTTP’), Session Initiation Protocol (‘SIP’), Real Time Protocol (‘RTP’), or the like.

Storage arrays 102A-B may provide persistent data storage for the computing devices 164A-B. Storage array 102A may be contained in a chassis (not shown), and storage array 102B may be contained in another chassis (not shown), in implementations. Storage array 102A and 102B may include one or more storage array controllers 110A-D (also referred to as “controller” herein). A storage array controller 110A-D may be embodied as a module of automated computing machinery comprising computer hardware, computer software, or a combination of computer hardware and software. In some implementations, the storage array controllers 110A-D may be configured to carry out various storage tasks. Storage tasks may include writing data received from the computing devices 164A-B to storage array 102A-B, erasing data from storage array 102A-B, retrieving data from storage array 102A-B and providing data to computing devices 164A-B, monitoring and reporting of disk utilization and performance, performing redundancy operations, such as Redundant Array of Independent Drives (RAID′) or RAID-like data redundancy operations, compressing data, encrypting data, and so forth.

Storage array controller 110A-D may be implemented in a variety of ways, including as a Field Programmable Gate Array (‘FPGA’), a Programmable Logic Chip (‘PLC’), an Application Specific Integrated Circuit (‘ASIC’), System-on-Chip (‘SOC’), or any computing device that includes discrete components such as a processing device, central processing unit, computer memory, or various adapters. Storage array controller 110A-D may include, for example, a data communications adapter configured to support communications via the SAN 158 or LAN 160. In some implementations, storage array controller 110A-D may be independently coupled to the LAN 160. In implementations, storage array controller 110A-D may include an I/O controller or the like that couples the storage array controller 110A-D for data communications, through a midplane (not shown), to a persistent storage resource 170A-B (also referred to as a “storage resource” herein). The persistent storage resource 170A-B main include any number of storage drives 171A-F (also referred to as “storage devices” herein) and any number of non-volatile Random Access Memory (‘NVRAM’) devices (not shown).

In some implementations, the NVRAM devices of a persistent storage resource 170A-B may be configured to receive, from the storage array controller 110A-D, data to be stored in the storage drives 171A-F. In some examples, the data may originate from computing devices 164A-B. In some examples, writing data to the NVRAM device may be carried out more quickly than directly writing data to the storage drive 171A-F. In implementations, the storage array controller 110A-D may be configured to utilize the NVRAM devices as a quickly accessible buffer for data destined to be written to the storage drives 171A-F. Latency for write requests using NVRAM devices as a buffer may be improved relative to a system in which a storage array controller 110A-D writes data directly to the storage drives 171A-F. In some implementations, the NVRAM devices may be implemented with computer memory in the form of high bandwidth, low latency RAM. The NVRAM device is referred to as “non-volatile” because the NVRAM device may receive or include a unique power source that maintains the state of the RAM after main power loss to the NVRAM device. Such a power source may be a battery, one or more capacitors, or the like. In response to a power loss, the NVRAM device may be configured to write the contents of the RAM to a persistent storage, such as the storage drives 171A-F.

In implementations, storage drive 171A-F may refer to any device configured to record data persistently, where “persistently” or “persistent” refers as to a device's ability to maintain recorded data after loss of power. In some implementations, storage drive 171A-F may correspond to non-disk storage media. For example, the storage drive 171A-F may be one or more solid-state drives (‘SSDs’), flash memory based storage, any type of solid-state non-volatile memory, or any other type of non-mechanical storage device. In other implementations, storage drive 171A-F may include mechanical or spinning hard disk, such as hard-disk drives (‘HDD’).

In some implementations, the storage array controllers 110A-D may be configured for offloading device management responsibilities from storage drive 171A-F in storage array 102A-B. For example, storage array controllers 110A-D may manage control information that may describe the state of one or more memory blocks in the storage drives 171A-F. The control information may indicate, for example, that a particular memory block has failed and should no longer be written to, that a particular memory block contains boot code for a storage array controller 110A-D, the number of program-erase (‘P/E’) cycles that have been performed on a particular memory block, the age of data stored in a particular memory block, the type of data that is stored in a particular memory block, and so forth. In some implementations, the control information may be stored with an associated memory block as metadata. In other implementations, the control information for the storage drives 171A-F may be stored in one or more particular memory blocks of the storage drives 171A-F that are selected by the storage array controller 110A-D. The selected memory blocks may be tagged with an identifier indicating that the selected memory block contains control information. The identifier may be utilized by the storage array controllers 110A-D in conjunction with storage drives 171A-F to quickly identify the memory blocks that contain control information. For example, the storage controllers 110A-D may issue a command to locate memory blocks that contain control information. It may be noted that control information may be so large that parts of the control information may be stored in multiple locations, that the control information may be stored in multiple locations for purposes of redundancy, for example, or that the control information may otherwise be distributed across multiple memory blocks in the storage drive 171A-F.

In implementations, storage array controllers 110A-D may offload device management responsibilities from storage drives 171A-F of storage array 102A-B by retrieving, from the storage drives 171A-F, control information describing the state of one or more memory blocks in the storage drives 171A-F. Retrieving the control information from the storage drives 171A-F may be carried out, for example, by the storage array controller 110A-D querying the storage drives 171A-F for the location of control information for a particular storage drive 171A-F. The storage drives 171A-F may be configured to execute instructions that enable the storage drive 171A-F to identify the location of the control information. The instructions may be executed by a controller (not shown) associated with or otherwise located on the storage drive 171A-F and may cause the storage drive 171A-F to scan a portion of each memory block to identify the memory blocks that store control information for the storage drives 171A-F. The storage drives 171A-F may respond by sending a response message to the storage array controller 110A-D that includes the location of control information for the storage drive 171A-F. Responsive to receiving the response message, storage array controllers 110A-D may issue a request to read data stored at the address associated with the location of control information for the storage drives 171A-F.

In other implementations, the storage array controllers 110A-D may further offload device management responsibilities from storage drives 171A-F by performing, in response to receiving the control information, a storage drive management operation. A storage drive management operation may include, for example, an operation that is typically performed by the storage drive 171A-F (e.g., the controller (not shown) associated with a particular storage drive 171A-F). A storage drive management operation may include, for example, ensuring that data is not written to failed memory blocks within the storage drive 171A-F, ensuring that data is written to memory blocks within the storage drive 171A-F in such a way that adequate wear leveling is achieved, and so forth.

In implementations, storage array 102A-B may implement two or more storage array controllers 110A-D. For example, storage array 102A may include storage array controllers 110A and storage array controllers 110B. At a given instance, a single storage array controller 110A-D (e.g., storage array controller 110A) of a storage system 100 may be designated with primary status (also referred to as “primary controller” herein), and other storage array controllers 110A-D (e.g., storage array controller 110A) may be designated with secondary status (also referred to as “secondary controller” herein). The primary controller may have particular rights, such as permission to alter data in persistent storage resource 170A-B (e.g., writing data to persistent storage resource 170A-B). At least some of the rights of the primary controller may supersede the rights of the secondary controller. For instance, the secondary controller may not have permission to alter data in persistent storage resource 170A-B when the primary controller has the right. The status of storage array controllers 110A-D may change. For example, storage array controller 110A may be designated with secondary status, and storage array controller 110B may be designated with primary status.

In some implementations, a primary controller, such as storage array controller 110A, may serve as the primary controller for one or more storage arrays 102A-B, and a second controller, such as storage array controller 110B, may serve as the secondary controller for the one or more storage arrays 102A-B. For example, storage array controller 110A may be the primary controller for storage array 102A and storage array 102B, and storage array controller 110B may be the secondary controller for storage array 102A and 102B. In some implementations, storage array controllers 110C and 110D (also referred to as “storage processing modules”) may neither have primary or secondary status. Storage array controllers 110C and 110D, implemented as storage processing modules, may act as a communication interface between the primary and secondary controllers (e.g., storage array controllers 110A and 110B, respectively) and storage array 102B. For example, storage array controller 110A of storage array 102A may send a write request, via SAN 158, to storage array 102B. The write request may be received by both storage array controllers 110C and 110D of storage array 102B. Storage array controllers 110C and 110D facilitate the communication, e.g., send the write request to the appropriate storage drive 171A-F. It may be noted that in some implementations storage processing modules may be used to increase the number of storage drives controlled by the primary and secondary controllers.

In implementations, storage array controllers 110A-D are communicatively coupled, via a midplane (not shown), to one or more storage drives 171A-F and to one or more NVRAM devices (not shown) that are included as part of a storage array 102A-B. The storage array controllers 110A-D may be coupled to the midplane via one or more data communication links and the midplane may be coupled to the storage drives 171A-F and the NVRAM devices via one or more data communications links. The data communications links described herein are collectively illustrated by data communications links 108A-D and may include a Peripheral Component Interconnect Express (‘PCIe’) bus, for example.

FIG. 1B illustrates an example system for data storage, in accordance with some implementations. Storage array controller 101 illustrated in FIG. 1B may be similar to the storage array controllers 110A-D described with respect to FIG. 1A. In one example, storage array controller 101 may be similar to storage array controller 110A or storage array controller 110B. Storage array controller 101 includes numerous elements for purposes of illustration rather than limitation. It may be noted that storage array controller 101 may include the same, more, or fewer elements configured in the same or different manner in other implementations. It may be noted that elements of FIG. 1A may be included below to help illustrate features of storage array controller 101.

Storage array controller 101 may include one or more processing devices 104 and random access memory (‘RAM’) 111. Processing device 104 (or controller 101) represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processing device 104 (or controller 101) may be a complex instruction set computing (‘CISC’) microprocessor, reduced instruction set computing (‘RISC’) microprocessor, very long instruction word (‘VLIW’) microprocessor, or a processor implementing other instruction sets or processors implementing a combination of instruction sets. The processing device 104 (or controller 101) may also be one or more special-purpose processing devices such as an application specific integrated circuit (‘ASIC’), a field programmable gate array (‘FPGA’), a digital signal processor (‘DSP’), network processor, or the like.

The processing device 104 may be connected to the RAM 111 via a data communications link 106, which may be embodied as a high speed memory bus such as a Double-Data Rate 4 (‘DDR4’) bus. Stored in RAM 111 is an operating system 112. In some implementations, instructions 113 are stored in RAM 111. Instructions 113 may include computer program instructions for performing operations in in a direct-mapped flash storage system. In one embodiment, a direct-mapped flash storage system is one that that addresses data blocks within flash drives directly and without an address translation performed by the storage controllers of the flash drives.

In implementations, storage array controller 101 includes one or more host bus adapters 103A-C that are coupled to the processing device 104 via a data communications link 105A-C. In implementations, host bus adapters 103A-C may be computer hardware that connects a host system (e.g., the storage array controller) to other network and storage arrays. In some examples, host bus adapters 103A-C may be a Fibre Channel adapter that enables the storage array controller 101 to connect to a SAN, an Ethernet adapter that enables the storage array controller 101 to connect to a LAN, or the like. Host bus adapters 103A-C may be coupled to the processing device 104 via a data communications link 105A-C such as, for example, a PCIe bus.

In implementations, storage array controller 101 may include a host bus adapter 114 that is coupled to an expander 115. The expander 115 may be used to attach a host system to a larger number of storage drives. The expander 115 may, for example, be a SAS expander utilized to enable the host bus adapter 114 to attach to storage drives in an implementation where the host bus adapter 114 is embodied as a SAS controller.

In implementations, storage array controller 101 may include a switch 116 coupled to the processing device 104 via a data communications link 109. The switch 116 may be a computer hardware device that can create multiple endpoints out of a single endpoint, thereby enabling multiple devices to share a single endpoint. The switch 116 may, for example, be a PCIe switch that is coupled to a PCIe bus (e.g., data communications link 109) and presents multiple PCIe connection points to the midplane.

In implementations, storage array controller 101 includes a data communications link 107 for coupling the storage array controller 101 to other storage array controllers. In some examples, data communications link 107 may be a QuickPath Interconnect (QPI) interconnect.

A traditional storage system that uses traditional flash drives may implement a process across the flash drives that are part of the traditional storage system. For example, a higher level process of the storage system may initiate and control a process across the flash drives. However, a flash drive of the traditional storage system may include its own storage controller that also performs the process. Thus, for the traditional storage system, a higher level process (e.g., initiated by the storage system) and a lower level process (e.g., initiated by a storage controller of the storage system) may both be performed.

To resolve various deficiencies of a traditional storage system, operations may be performed by higher level processes and not by the lower level processes. For example, the flash storage system may include flash drives that do not include storage controllers that provide the process. Thus, the operating system of the flash storage system itself may initiate and control the process. This may be accomplished by a direct-mapped flash storage system that addresses data blocks within the flash drives directly and without an address translation performed by the storage controllers of the flash drives.

The operating system of the flash storage system may identify and maintain a list of allocation units across multiple flash drives of the flash storage system. The allocation units may be entire erase blocks or multiple erase blocks. The operating system may maintain a map or address range that directly maps addresses to erase blocks of the flash drives of the flash storage system.

Direct mapping to the erase blocks of the flash drives may be used to rewrite data and erase data. For example, the operations may be performed on one or more allocation units that include a first data and a second data where the first data is to be retained and the second data is no longer being used by the flash storage system. The operating system may initiate the process to write the first data to new locations within other allocation units and erasing the second data and marking the allocation units as being available for use for subsequent data. Thus, the process may only be performed by the higher level operating system of the flash storage system without an additional lower level process being performed by controllers of the flash drives.

Advantages of the process being performed only by the operating system of the flash storage system include increased reliability of the flash drives of the flash storage system as unnecessary or redundant write operations are not being performed during the process. One possible point of novelty here is the concept of initiating and controlling the process at the operating system of the flash storage system. In addition, the process can be controlled by the operating system across multiple flash drives. This is contrast to the process being performed by a storage controller of a flash drive.

A storage system can consist of two storage array controllers that share a set of drives for failover purposes, or it could consist of a single storage array controller that provides a storage service that utilizes multiple drives, or it could consist of a distributed network of storage array controllers each with some number of drives or some amount of Flash storage where the storage array controllers in the network collaborate to provide a complete storage service and collaborate on various aspects of a storage service including storage allocation and garbage collection.

FIG. 1C illustrates a third example system 117 for data storage in accordance with some implementations. System 117 (also referred to as “storage system” herein) includes numerous elements for purposes of illustration rather than limitation. It may be noted that system 117 may include the same, more, or fewer elements configured in the same or different manner in other implementations.

In one embodiment, system 117 includes a dual Peripheral Component Interconnect (‘PCI’) flash storage device 118 with separately addressable fast write storage. System 117 may include a storage controller 119. In one embodiment, storage controller 119A-D may be a CPU, ASIC, FPGA, or any other circuitry that may implement control structures necessary according to the present disclosure. In one embodiment, system 117 includes flash memory devices (e.g., including flash memory devices 120 a-n), operatively coupled to various channels of the storage device controller 119. Flash memory devices 120 a-n, may be presented to the controller 119A-D as an addressable collection of Flash pages, erase blocks, and/or control elements sufficient to allow the storage device controller 119A-D to program and retrieve various aspects of the Flash. In one embodiment, storage device controller 119A-D may perform operations on flash memory devices 120 a-n including storing and retrieving data content of pages, arranging and erasing any blocks, tracking statistics related to the use and reuse of Flash memory pages, erase blocks, and cells, tracking and predicting error codes and faults within the Flash memory, controlling voltage levels associated with programming and retrieving contents of Flash cells, etc.

In one embodiment, system 117 may include RAM 121 to store separately addressable fast-write data. In one embodiment, RAM 121 may be one or more separate discrete devices. In another embodiment, RAM 121 may be integrated into storage device controller 119A-D or multiple storage device controllers. The RAM 121 may be utilized for other purposes as well, such as temporary program memory for a processing device (e.g., a CPU) in the storage device controller 119.

In one embodiment, system 117 may include a stored energy device 122, such as a rechargeable battery or a capacitor. Stored energy device 122 may store energy sufficient to power the storage device controller 119, some amount of the RAM (e.g., RAM 121), and some amount of Flash memory (e.g., Flash memory 120 a-120 n) for sufficient time to write the contents of RAM to Flash memory. In one embodiment, storage device controller 119A-D may write the contents of RAM to Flash Memory if the storage device controller detects loss of external power.

In one embodiment, system 117 includes two data communications links 123 a, 123 b. In one embodiment, data communications links 123 a, 123 b may be PCI interfaces. In another embodiment, data communications links 123 a, 123 b may be based on other communications standards (e.g., HyperTransport, InfiniBand, etc.). Data communications links 123 a, 123 b may be based on non-volatile memory express (‘NVMe’) or NVMe over fabrics (‘NVMf’) specifications that allow external connection to the storage device controller 119A-D from other components in the storage system 117. It should be noted that data communications links may be interchangeably referred to herein as PCI buses for convenience.

System 117 may also include an external power source (not shown), which may be provided over one or both data communications links 123 a, 123 b, or which may be provided separately. An alternative embodiment includes a separate Flash memory (not shown) dedicated for use in storing the content of RAM 121. The storage device controller 119A-D may present a logical device over a PCI bus which may include an addressable fast-write logical device, or a distinct part of the logical address space of the storage device 118, which may be presented as PCI memory or as persistent storage. In one embodiment, operations to store into the device are directed into the RAM 121. On power failure, the storage device controller 119A-D may write stored content associated with the addressable fast-write logical storage to Flash memory (e.g., Flash memory 120 a-n) for long-term persistent storage.

In one embodiment, the logical device may include some presentation of some or all of the content of the Flash memory devices 120 a-n, where that presentation allows a storage system including a storage device 118 (e.g., storage system 117) to directly address Flash memory pages and directly reprogram erase blocks from storage system components that are external to the storage device through the PCI bus. The presentation may also allow one or more of the external components to control and retrieve other aspects of the Flash memory including some or all of: tracking statistics related to use and reuse of Flash memory pages, erase blocks, and cells across all the Flash memory devices; tracking and predicting error codes and faults within and across the Flash memory devices; controlling voltage levels associated with programming and retrieving contents of Flash cells; etc.

In one embodiment, the stored energy device 122 may be sufficient to ensure completion of in-progress operations to the Flash memory devices 120 a-120 n stored energy device 122 may power storage device controller 119A-D and associated Flash memory devices (e.g., 120 a-n) for those operations, as well as for the storing of fast-write RAM to Flash memory. Stored energy device 122 may be used to store accumulated statistics and other parameters kept and tracked by the Flash memory devices 120 a-n and/or the storage device controller 119. Separate capacitors or stored energy devices (such as smaller capacitors near or embedded within the Flash memory devices themselves) may be used for some or all of the operations described herein.

Various schemes may be used to track and optimize the life span of the stored energy component, such as adjusting voltage levels over time, partially discharging the storage energy device 122 to measure corresponding discharge characteristics, etc. If the available energy decreases over time, the effective available capacity of the addressable fast-write storage may be decreased to ensure that it can be written safely based on the currently available stored energy.

FIG. 1D illustrates a third example system 124 for data storage in accordance with some implementations. In one embodiment, system 124 includes storage controllers 125 a, 125 b. In one embodiment, storage controllers 125 a, 125 b are operatively coupled to Dual PCI storage devices 119 a, 119 b and 119 c, 119 d, respectively. Storage controllers 125 a, 125 b may be operatively coupled (e.g., via a storage network 130) to some number of host computers 127 a-n.

In one embodiment, two storage controllers (e.g., 125 a and 125 b) provide storage services, such as a SCS) block storage array, a file server, an object server, a database or data analytics service, etc. The storage controllers 125 a, 125 b may provide services through some number of network interfaces (e.g., 126 a-d) to host computers 127 a-n outside of the storage system 124. Storage controllers 125 a, 125 b may provide integrated services or an application entirely within the storage system 124, forming a converged storage and compute system. The storage controllers 125 a, 125 b may utilize the fast write memory within or across storage devices 119 a-d to journal in progress operations to ensure the operations are not lost on a power failure, storage controller removal, storage controller or storage system shutdown, or some fault of one or more software or hardware components within the storage system 124.

In one embodiment, controllers 125 a, 125 b operate as PCI masters to one or the other PCI buses 128 a, 128 b. In another embodiment, 128 a and 128 b may be based on other communications standards (e.g., HyperTransport, InfiniBand, etc.). Other storage system embodiments may operate storage controllers 125 a, 125 b as multi-masters for both PCI buses 128 a, 128 b. Alternately, a PCI/NVMe/NVMf switching infrastructure or fabric may connect multiple storage controllers. Some storage system embodiments may allow storage devices to communicate with each other directly rather than communicating only with storage controllers. In one embodiment, a storage device controller 119 a may be operable under direction from a storage controller 125 a to synthesize and transfer data to be stored into Flash memory devices from data that has been stored in RAM (e.g., RAM 121 of FIG. 1C). For example, a recalculated version of RAM content may be transferred after a storage controller has determined that an operation has fully committed across the storage system, or when fast-write memory on the device has reached a certain used capacity, or after a certain amount of time, to ensure improve safety of the data or to release addressable fast-write capacity for reuse. This mechanism may be used, for example, to avoid a second transfer over a bus (e.g., 128 a, 128 b) from the storage controllers 125 a, 125 b. In one embodiment, a recalculation may include compressing data, attaching indexing or other metadata, combining multiple data segments together, performing erasure code calculations, etc.

In one embodiment, under direction from a storage controller 125 a, 125 b, a storage device controller 119 a, 119 b may be operable to calculate and transfer data to other storage devices from data stored in RAM (e.g., RAM 121 of FIG. 1C) without involvement of the storage controllers 125 a, 125 b. This operation may be used to mirror data stored in one controller 125 a to another controller 125 b, or it could be used to offload compression, data aggregation, and/or erasure coding calculations and transfers to storage devices to reduce load on storage controllers or the storage controller interface 129 a, 129 b to the PCI bus 128 a, 128 b.

A storage device controller 119A-D may include mechanisms for implementing high availability primitives for use by other parts of a storage system external to the Dual PCI storage device 118. For example, reservation or exclusion primitives may be provided so that, in a storage system with two storage controllers providing a highly available storage service, one storage controller may prevent the other storage controller from accessing or continuing to access the storage device. This could be used, for example, in cases where one controller detects that the other controller is not functioning properly or where the interconnect between the two storage controllers may itself not be functioning properly.

In one embodiment, a storage system for use with Dual PCI direct mapped storage devices with separately addressable fast write storage includes systems that manage erase blocks or groups of erase blocks as allocation units for storing data on behalf of the storage service, or for storing metadata (e.g., indexes, logs, etc.) associated with the storage service, or for proper management of the storage system itself. Flash pages, which may be a few kilobytes in size, may be written as data arrives or as the storage system is to persist data for long intervals of time (e.g., above a defined threshold of time). To commit data more quickly, or to reduce the number of writes to the Flash memory devices, the storage controllers may first write data into the separately addressable fast write storage on one more storage devices.

In one embodiment, the storage controllers 125 a, 125 b may initiate the use of erase blocks within and across storage devices (e.g., 118) in accordance with an age and expected remaining lifespan of the storage devices, or based on other statistics. The storage controllers 125 a, 125 b may initiate garbage collection and data migration data between storage devices in accordance with pages that are no longer needed as well as to manage Flash page and erase block lifespans and to manage overall system performance.

In one embodiment, the storage system 124 may utilize mirroring and/or erasure coding schemes as part of storing data into addressable fast write storage and/or as part of writing data into allocation units associated with erase blocks. Erasure codes may be used across storage devices, as well as within erase blocks or allocation units, or within and across Flash memory devices on a single storage device, to provide redundancy against single or multiple storage device failures or to protect against internal corruptions of Flash memory pages resulting from Flash memory operations or from degradation of Flash memory cells. Mirroring and erasure coding at various levels may be used to recover from multiple types of failures that occur separately or in combination.

The embodiments depicted with reference to FIGS. 2A-G illustrate a storage cluster that stores user data, such as user data originating from one or more user or client systems or other sources external to the storage cluster. The storage cluster distributes user data across storage nodes housed within a chassis, or across multiple chassis, using erasure coding and redundant copies of metadata. Erasure coding refers to a method of data protection or reconstruction in which data is stored across a set of different locations, such as disks, storage nodes or geographic locations. Flash memory is one type of solid-state memory that may be integrated with the embodiments, although the embodiments may be extended to other types of solid-state memory or other storage medium, including non-solid state memory. Control of storage locations and workloads are distributed across the storage locations in a clustered peer-to-peer system. Tasks such as mediating communications between the various storage nodes, detecting when a storage node has become unavailable, and balancing I/Os (inputs and outputs) across the various storage nodes, are all handled on a distributed basis. Data is laid out or distributed across multiple storage nodes in data fragments or stripes that support data recovery in some embodiments. Ownership of data can be reassigned within a cluster, independent of input and output patterns. This architecture described in more detail below allows a storage node in the cluster to fail, with the system remaining operational, since the data can be reconstructed from other storage nodes and thus remain available for input and output operations. In various embodiments, a storage node may be referred to as a cluster node, a blade, or a server.

The storage cluster may be contained within a chassis, i.e., an enclosure housing one or more storage nodes. A mechanism to provide power to each storage node, such as a power distribution bus, and a communication mechanism, such as a communication bus that enables communication between the storage nodes are included within the chassis. The storage cluster can run as an independent system in one location according to some embodiments. In one embodiment, a chassis contains at least two instances of both the power distribution and the communication bus which may be enabled or disabled independently. The internal communication bus may be an Ethernet bus, however, other technologies such as PCIe, InfiniBand, and others, are equally suitable. The chassis provides a port for an external communication bus for enabling communication between multiple chassis, directly or through a switch, and with client systems. The external communication may use a technology such as Ethernet, InfiniBand, Fibre Channel, etc. In some embodiments, the external communication bus uses different communication bus technologies for inter-chassis and client communication. If a switch is deployed within or between chassis, the switch may act as a translation between multiple protocols or technologies. When multiple chassis are connected to define a storage cluster, the storage cluster may be accessed by a client using either proprietary interfaces or standard interfaces such as network file system (‘NFS’), common internet file system (‘CIFS’), small computer system interface (‘SCSI’) or hypertext transfer protocol (‘HTTP’). Translation from the client protocol may occur at the switch, chassis external communication bus or within each storage node. In some embodiments, multiple chassis may be coupled or connected to each other through an aggregator switch. A portion and/or all of the coupled or connected chassis may be designated as a storage cluster. As discussed above, each chassis can have multiple blades, each blade has a media access control (‘MAC’) address, but the storage cluster is presented to an external network as having a single cluster IP address and a single MAC address in some embodiments.

Each storage node may be one or more storage servers and each storage server is connected to one or more non-volatile solid state memory units, which may be referred to as storage units or storage devices. One embodiment includes a single storage server in each storage node and between one to eight non-volatile solid state memory units, however this one example is not meant to be limiting. The storage server may include a processor, DRAM and interfaces for the internal communication bus and power distribution for each of the power buses. Inside the storage node, the interfaces and storage unit share a communication bus, e.g., PCI Express, in some embodiments. The non-volatile solid state memory units may directly access the internal communication bus interface through a storage node communication bus, or request the storage node to access the bus interface. The non-volatile solid state memory unit contains an embedded CPU, solid state storage controller, and a quantity of solid state mass storage, e.g., between 2-32 terabytes (‘TB’) in some embodiments. An embedded volatile storage medium, such as DRAM, and an energy reserve apparatus are included in the non-volatile solid state memory unit. In some embodiments, the energy reserve apparatus is a capacitor, super-capacitor, or battery that enables transferring a subset of DRAM contents to a stable storage medium in the case of power loss. In some embodiments, the non-volatile solid state memory unit is constructed with a storage class memory, such as phase change or magnetoresistive random access memory (‘MRAM’) that substitutes for DRAM and enables a reduced power hold-up apparatus.

One of many features of the storage nodes and non-volatile solid state storage is the ability to proactively rebuild data in a storage cluster. The storage nodes and non-volatile solid state storage can determine when a storage node or non-volatile solid state storage in the storage cluster is unreachable, independent of whether there is an attempt to read data involving that storage node or non-volatile solid state storage. The storage nodes and non-volatile solid state storage then cooperate to recover and rebuild the data in at least partially new locations. This constitutes a proactive rebuild, in that the system rebuilds data without waiting until the data is needed for a read access initiated from a client system employing the storage cluster. These and further details of the storage memory and operation thereof are discussed below.

FIG. 2A is a perspective view of a storage cluster 161, with multiple storage nodes 150 and internal solid-state memory coupled to each storage node to provide network attached storage or storage area network, in accordance with some embodiments. A network attached storage, storage area network, or a storage cluster, or other storage memory, could include one or more storage clusters 161, each having one or more storage nodes 150, in a flexible and reconfigurable arrangement of both the physical components and the amount of storage memory provided thereby. The storage cluster 161 is designed to fit in a rack, and one or more racks can be set up and populated as desired for the storage memory. The storage cluster 161 has a chassis 138 having multiple slots 142. It should be appreciated that chassis 138 may be referred to as a housing, enclosure, or rack unit. In one embodiment, the chassis 138 has fourteen slots 142, although other numbers of slots are readily devised. For example, some embodiments have four slots, eight slots, sixteen slots, thirty-two slots, or other suitable number of slots. Each slot 142 can accommodate one storage node 150 in some embodiments. Chassis 138 includes flaps 148 that can be utilized to mount the chassis 138 on a rack. Fans 144 provide air circulation for cooling of the storage nodes 150 and components thereof, although other cooling components could be used, or an embodiment could be devised without cooling components. A switch fabric 146 couples storage nodes 150 within chassis 138 together and to a network for communication to the memory. In an embodiment depicted in herein, the slots 142 to the left of the switch fabric 146 and fans 144 are shown occupied by storage nodes 150, while the slots 142 to the right of the switch fabric 146 and fans 144 are empty and available for insertion of storage node 150 for illustrative purposes. This configuration is one example, and one or more storage nodes 150 could occupy the slots 142 in various further arrangements. The storage node arrangements need not be sequential or adjacent in some embodiments. Storage nodes 150 are hot pluggable, meaning that a storage node 150 can be inserted into a slot 142 in the chassis 138, or removed from a slot 142, without stopping or powering down the system. Upon insertion or removal of storage node 150 from slot 142, the system automatically reconfigures in order to recognize and adapt to the change. Reconfiguration, in some embodiments, includes restoring redundancy and/or rebalancing data or load.

Each storage node 150 can have multiple components. In the embodiment shown here, the storage node 150 includes a printed circuit board 159 populated by a CPU 156, i.e., processor, a memory 154 coupled to the CPU 156, and a non-volatile solid state storage 152 coupled to the CPU 156, although other mountings and/or components could be used in further embodiments. The memory 154 has instructions which are executed by the CPU 156 and/or data operated on by the CPU 156. As further explained below, the non-volatile solid state storage 152 includes flash or, in further embodiments, other types of solid-state memory.

Referring to FIG. 2A, storage cluster 161 is scalable, meaning that storage capacity with non-uniform storage sizes is readily added, as described above. One or more storage nodes 150 can be plugged into or removed from each chassis and the storage cluster self-configures in some embodiments. Plug-in storage nodes 150, whether installed in a chassis as delivered or later added, can have different sizes. For example, in one embodiment a storage node 150 can have any multiple of 4 TB, e.g., 8 TB, 12 TB, 16 TB, 32 TB, etc. In further embodiments, a storage node 150 could have any multiple of other storage amounts or capacities. Storage capacity of each storage node 150 is broadcast, and influences decisions of how to stripe the data. For maximum storage efficiency, an embodiment can self-configure as wide as possible in the stripe, subject to a predetermined requirement of continued operation with loss of up to one, or up to two, non-volatile solid state storage units 152 or storage nodes 150 within the chassis.

FIG. 2B is a block diagram showing a communications interconnect 173 and power distribution bus 172 coupling multiple storage nodes 150. Referring back to FIG. 2A, the communications interconnect 173 can be included in or implemented with the switch fabric 146 in some embodiments. Where multiple storage clusters 161 occupy a rack, the communications interconnect 173 can be included in or implemented with a top of rack switch, in some embodiments. As illustrated in FIG. 2B, storage cluster 161 is enclosed within a single chassis 138. External port 176 is coupled to storage nodes 150 through communications interconnect 173, while external port 174 is coupled directly to a storage node. External power port 178 is coupled to power distribution bus 172. Storage nodes 150 may include varying amounts and differing capacities of non-volatile solid state storage 152 as described with reference to FIG. 2A. In addition, one or more storage nodes 150 may be a compute only storage node as illustrated in FIG. 2B. Authorities 168 are implemented on the non-volatile solid state storages 152, for example as lists or other data structures stored in memory. In some embodiments the authorities are stored within the non-volatile solid state storage 152 and supported by software executing on a controller or other processor of the non-volatile solid state storage 152. In a further embodiment, authorities 168 are implemented on the storage nodes 150, for example as lists or other data structures stored in the memory 154 and supported by software executing on the CPU 156 of the storage node 150. Authorities 168 control how and where data is stored in the non-volatile solid state storages 152 in some embodiments. This control assists in determining which type of erasure coding scheme is applied to the data, and which storage nodes 150 have which portions of the data. Each authority 168 may be assigned to a non-volatile solid state storage 152. Each authority may control a range of inode numbers, segment numbers, or other data identifiers which are assigned to data by a file system, by the storage nodes 150, or by the non-volatile solid state storage 152, in various embodiments.

Every piece of data, and every piece of metadata, has redundancy in the system in some embodiments. In addition, every piece of data and every piece of metadata has an owner, which may be referred to as an authority. If that authority is unreachable, for example through failure of a storage node, there is a plan of succession for how to find that data or that metadata. In various embodiments, there are redundant copies of authorities 168. Authorities 168 have a relationship to storage nodes 150 and non-volatile solid state storage 152 in some embodiments. Each authority 168, covering a range of data segment numbers or other identifiers of the data, may be assigned to a specific non-volatile solid state storage 152. In some embodiments the authorities 168 for all of such ranges are distributed over the non-volatile solid state storages 152 of a storage cluster. Each storage node 150 has a network port that provides access to the non-volatile solid state storage(s) 152 of that storage node 150. Data can be stored in a segment, which is associated with a segment number and that segment number is an indirection for a configuration of a RAID (redundant array of independent disks) stripe in some embodiments. The assignment and use of the authorities 168 thus establishes an indirection to data. Indirection may be referred to as the ability to reference data indirectly, in this case via an authority 168, in accordance with some embodiments. A segment identifies a set of non-volatile solid state storage 152 and a local identifier into the set of non-volatile solid state storage 152 that may contain data. In some embodiments, the local identifier is an offset into the device and may be reused sequentially by multiple segments. In some embodiments the local identifier is unique for a specific segment and never reused. The offsets in the non-volatile solid state storage 152 are applied to locating data for writing to or reading from the non-volatile solid state storage 152 (in the form of a RAID stripe). Data is striped across multiple units of non-volatile solid state storage 152, which may include or be different from the non-volatile solid state storage 152 having the authority 168 for a particular data segment.

If there is a change in where a particular segment of data is located, e.g., during a data move or a data reconstruction, the authority 168 for that data segment should be consulted, at that non-volatile solid state storage 152 or storage node 150 having that authority 168. In order to locate a particular piece of data, embodiments calculate a hash value for a data segment or apply an inode number or a data segment number. The output of this operation points to a non-volatile solid state storage 152 having the authority 168 for that particular piece of data. In some embodiments there are two stages to this operation. The first stage maps an entity identifier (ID), e.g., a segment number, inode number, or directory number to an authority identifier. This mapping may include a calculation such as a hash or a bit mask. The second stage is mapping the authority identifier to a particular non-volatile solid state storage 152, which may be done through an explicit mapping. The operation is repeatable, so that when the calculation is performed, the result of the calculation repeatably and reliably points to a particular non-volatile solid state storage 152 having that authority 168. The operation may include the set of reachable storage nodes as input. If the set of reachable non-volatile solid state storage units changes the optimal set changes. In some embodiments, the persisted value is the current assignment (which is always true) and the calculated value is the target assignment the cluster will attempt to reconfigure towards. This calculation may be used to determine the optimal non-volatile solid state storage 152 for an authority in the presence of a set of non-volatile solid state storage 152 that are reachable and constitute the same cluster. The calculation also determines an ordered set of peer non-volatile solid state storage 152 that will also record the authority to non-volatile solid state storage mapping so that the authority may be determined even if the assigned non-volatile solid state storage is unreachable. A duplicate or substitute authority 168 may be consulted if a specific authority 168 is unavailable in some embodiments.

With reference to FIGS. 2A and 2B, two of the many tasks of the CPU 156 on a storage node 150 are to break up write data, and reassemble read data. When the system has determined that data is to be written, the authority 168 for that data is located as above. When the segment ID for data is already determined the request to write is forwarded to the non-volatile solid state storage 152 currently determined to be the host of the authority 168 determined from the segment. The host CPU 156 of the storage node 150, on which the non-volatile solid state storage 152 and corresponding authority 168 reside, then breaks up or shards the data and transmits the data out to various non-volatile solid state storage 152. The transmitted data is written as a data stripe in accordance with an erasure coding scheme. In some embodiments, data is requested to be pulled, and in some embodiments, data is pushed. In reverse, when data is read, the authority 168 for the segment ID containing the data is located as described above. The host CPU 156 of the storage node 150 on which the non-volatile solid state storage 152 and corresponding authority 168 reside requests the data from the non-volatile solid state storage and corresponding storage nodes pointed to by the authority. In some embodiments the data is read from flash storage as a data stripe. The host CPU 156 of storage node 150 then reassembles the read data, correcting any errors (if present) according to the appropriate erasure coding scheme, and forwards the reassembled data to the network. In further embodiments, some or all of these tasks can be handled in the non-volatile solid state storage 152. In some embodiments, the segment host requests the data be sent to storage node 150 by requesting pages from storage and then sending the data to the storage node making the original request.

In some systems, for example in UNIX-style file systems, data is handled with an index node or inode, which specifies a data structure that represents an object in a file system. The object could be a file or a directory, for example. Metadata may accompany the object, as attributes such as permission data and a creation timestamp, among other attributes. A segment number could be assigned to all or a portion of such an object in a file system. In other systems, data segments are handled with a segment number assigned elsewhere. For purposes of discussion, the unit of distribution is an entity, and an entity can be a file, a directory or a segment. That is, entities are units of data or metadata stored by a storage system. Entities are grouped into sets called authorities. Each authority has an authority owner, which is a storage node that has the exclusive right to update the entities in the authority. In other words, a storage node contains the authority, and that the authority, in turn, contains entities.

A segment is a logical container of data in accordance with some embodiments. A segment is an address space between medium address space and physical flash locations, i.e., the data segment number, are in this address space. Segments may also contain meta-data, which enable data redundancy to be restored (rewritten to different flash locations or devices) without the involvement of higher level software. In one embodiment, an internal format of a segment contains client data and medium mappings to determine the position of that data. Each data segment is protected, e.g., from memory and other failures, by breaking the segment into a number of data and parity shards, where applicable. The data and parity shards are distributed, i.e., striped, across non-volatile solid state storage 152 coupled to the host CPUs 156 (See FIGS. 2E and 2G) in accordance with an erasure coding scheme. Usage of the term segments refers to the container and its place in the address space of segments in some embodiments. Usage of the term stripe refers to the same set of shards as a segment and includes how the shards are distributed along with redundancy or parity information in accordance with some embodiments.

A series of address-space transformations takes place across an entire storage system. At the top are the directory entries (file names) which link to an inode. Inodes point into medium address space, where data is logically stored. Medium addresses may be mapped through a series of indirect mediums to spread the load of large files, or implement data services like deduplication or snapshots. Medium addresses may be mapped through a series of indirect mediums to spread the load of large files, or implement data services like deduplication or snapshots. Segment addresses are then translated into physical flash locations. Physical flash locations have an address range bounded by the amount of flash in the system in accordance with some embodiments. Medium addresses and segment addresses are logical containers, and in some embodiments use a 128 bit or larger identifier so as to be practically infinite, with a likelihood of reuse calculated as longer than the expected life of the system. Addresses from logical containers are allocated in a hierarchical fashion in some embodiments. Initially, each non-volatile solid state storage unit 152 may be assigned a range of address space. Within this assigned range, the non-volatile solid state storage 152 is able to allocate addresses without synchronization with other non-volatile solid state storage 152.

Data and metadata is stored by a set of underlying storage layouts that are optimized for varying workload patterns and storage devices. These layouts incorporate multiple redundancy schemes, compression formats and index algorithms. Some of these layouts store information about authorities and authority masters, while others store file metadata and file data. The redundancy schemes include error correction codes that tolerate corrupted bits within a single storage device (such as a NAND flash chip), erasure codes that tolerate the failure of multiple storage nodes, and replication schemes that tolerate data center or regional failures. In some embodiments, low density parity check (‘LDPC’) code is used within a single storage unit. Reed-Solomon encoding is used within a storage cluster, and mirroring is used within a storage grid in some embodiments. Metadata may be stored using an ordered log structured index (such as a Log Structured Merge Tree), and large data may not be stored in a log structured layout.

In order to maintain consistency across multiple copies of an entity, the storage nodes agree implicitly on two things through calculations: (1) the authority that contains the entity, and (2) the storage node that contains the authority. The assignment of entities to authorities can be done by pseudo randomly assigning entities to authorities, by splitting entities into ranges based upon an externally produced key, or by placing a single entity into each authority. Examples of pseudorandom schemes are linear hashing and the Replication Under Scalable Hashing (‘RUSH’) family of hashes, including Controlled Replication Under Scalable Hashing (‘CRUSH’). In some embodiments, pseudo-random assignment is utilized only for assigning authorities to nodes because the set of nodes can change. The set of authorities cannot change so any subjective function may be applied in these embodiments. Some placement schemes automatically place authorities on storage nodes, while other placement schemes rely on an explicit mapping of authorities to storage nodes. In some embodiments, a pseudorandom scheme is utilized to map from each authority to a set of candidate authority owners. A pseudorandom data distribution function related to CRUSH may assign authorities to storage nodes and create a list of where the authorities are assigned. Each storage node has a copy of the pseudorandom data distribution function, and can arrive at the same calculation for distributing, and later finding or locating an authority. Each of the pseudorandom schemes requires the reachable set of storage nodes as input in some embodiments in order to conclude the same target nodes. Once an entity has been placed in an authority, the entity may be stored on physical devices so that no expected failure will lead to unexpected data loss. In some embodiments, rebalancing algorithms attempt to store the copies of all entities within an authority in the same layout and on the same set of machines.

Examples of expected failures include device failures, stolen machines, datacenter fires, and regional disasters, such as nuclear or geological events. Different failures lead to different levels of acceptable data loss. In some embodiments, a stolen storage node impacts neither the security nor the reliability of the system, while depending on system configuration, a regional event could lead to no loss of data, a few seconds or minutes of lost updates, or even complete data loss.

In the embodiments, the placement of data for storage redundancy is independent of the placement of authorities for data consistency. In some embodiments, storage nodes that contain authorities do not contain any persistent storage. Instead, the storage nodes are connected to non-volatile solid state storage units that do not contain authorities. The communications interconnect between storage nodes and non-volatile solid state storage units consists of multiple communication technologies and has non-uniform performance and fault tolerance characteristics. In some embodiments, as mentioned above, non-volatile solid state storage units are connected to storage nodes via PCI express, storage nodes are connected together within a single chassis using Ethernet backplane, and chassis are connected together to form a storage cluster. Storage clusters are connected to clients using Ethernet or fiber channel in some embodiments. If multiple storage clusters are configured into a storage grid, the multiple storage clusters are connected using the Internet or other long-distance networking links, such as a “metro scale” link or private link that does not traverse the internet.

Authority owners have the exclusive right to modify entities, to migrate entities from one non-volatile solid state storage unit to another non-volatile solid state storage unit, and to add and remove copies of entities. This allows for maintaining the redundancy of the underlying data. When an authority owner fails, is going to be decommissioned, or is overloaded, the authority is transferred to a new storage node. Transient failures make it non-trivial to ensure that all non-faulty machines agree upon the new authority location. The ambiguity that arises due to transient failures can be achieved automatically by a consensus protocol such as Paxos, hot-warm failover schemes, via manual intervention by a remote system administrator, or by a local hardware administrator (such as by physically removing the failed machine from the cluster, or pressing a button on the failed machine). In some embodiments, a consensus protocol is used, and failover is automatic. If too many failures or replication events occur in too short a time period, the system goes into a self-preservation mode and halts replication and data movement activities until an administrator intervenes in accordance with some embodiments.

As authorities are transferred between storage nodes and authority owners update entities in their authorities, the system transfers messages between the storage nodes and non-volatile solid state storage units. With regard to persistent messages, messages that have different purposes are of different types. Depending on the type of the message, the system maintains different ordering and durability guarantees. As the persistent messages are being processed, the messages are temporarily stored in multiple durable and non-durable storage hardware technologies. In some embodiments, messages are stored in RAM, NVRAM and on NAND flash devices, and a variety of protocols are used in order to make efficient use of each storage medium. Latency-sensitive client requests may be persisted in replicated NVRAM, and then later NAND, while background rebalancing operations are persisted directly to NAND.

Persistent messages are persistently stored prior to being transmitted. This allows the system to continue to serve client requests despite failures and component replacement. Although many hardware components contain unique identifiers that are visible to system administrators, manufacturer, hardware supply chain and ongoing monitoring quality control infrastructure, applications running on top of the infrastructure address virtualize addresses. These virtualized addresses do not change over the lifetime of the storage system, regardless of component failures and replacements. This allows each component of the storage system to be replaced over time without reconfiguration or disruptions of client request processing, i.e., the system supports non-disruptive upgrades.

In some embodiments, the virtualized addresses are stored with sufficient redundancy. A continuous monitoring system correlates hardware and software status and the hardware identifiers. This allows detection and prediction of failures due to faulty components and manufacturing details. The monitoring system also enables the proactive transfer of authorities and entities away from impacted devices before failure occurs by removing the component from the critical path in some embodiments.

FIG. 2C is a multiple level block diagram, showing contents of a storage node 150 and contents of a non-volatile solid state storage 152 of the storage node 150. Data is communicated to and from the storage node 150 by a network interface controller (‘NIC’) 202 in some embodiments. Each storage node 150 has a CPU 156, and one or more non-volatile solid state storage 152, as discussed above. Moving down one level in FIG. 2C, each non-volatile solid state storage 152 has a relatively fast non-volatile solid state memory, such as nonvolatile random access memory (‘NVRAM’) 204, and flash memory 206. In some embodiments, NVRAM 204 may be a component that does not require program/erase cycles (DRAM, MRAM, PCM), and can be a memory that can support being written vastly more often than the memory is read from. Moving down another level in FIG. 2C, the NVRAM 204 is implemented in one embodiment as high speed volatile memory, such as dynamic random access memory (DRAM) 216, backed up by energy reserve 218. Energy reserve 218 provides sufficient electrical power to keep the DRAM 216 powered long enough for contents to be transferred to the flash memory 206 in the event of power failure. In some embodiments, energy reserve 218 is a capacitor, super-capacitor, battery, or other device, that supplies a suitable supply of energy sufficient to enable the transfer of the contents of DRAM 216 to a stable storage medium in the case of power loss. The flash memory 206 is implemented as multiple flash dies 222, which may be referred to as packages of flash dies 222 or an array of flash dies 222. It should be appreciated that the flash dies 222 could be packaged in any number of ways, with a single die per package, multiple dies per package (i.e. multichip packages), in hybrid packages, as bare dies on a printed circuit board or other substrate, as encapsulated dies, etc. In the embodiment shown, the non-volatile solid state storage 152 has a controller 212 or other processor, and an input output (I/O) port 210 coupled to the controller 212. I/O port 210 is coupled to the CPU 156 and/or the network interface controller 202 of the flash storage node 150. Flash input output (I/O) port 220 is coupled to the flash dies 222, and a direct memory access unit (DMA) 214 is coupled to the controller 212, the DRAM 216 and the flash dies 222. In the embodiment shown, the I/O port 210, controller 212, DMA unit 214 and flash I/O port 220 are implemented on a programmable logic device (‘PLD’) 208, e.g., a field programmable gate array (FPGA). In this embodiment, each flash die 222 has pages, organized as sixteen kB (kilobyte) pages 224, and a register 226 through which data can be written to or read from the flash die 222. In further embodiments, other types of solid-state memory are used in place of, or in addition to flash memory illustrated within flash die 222.

Storage clusters 161, in various embodiments as disclosed herein, can be contrasted with storage arrays in general. The storage nodes 150 are part of a collection that creates the storage cluster 161. Each storage node 150 owns a slice of data and computing required to provide the data. Multiple storage nodes 150 cooperate to store and retrieve the data. Storage memory or storage devices, as used in storage arrays in general, are less involved with processing and manipulating the data. Storage memory or storage devices in a storage array receive commands to read, write, or erase data. The storage memory or storage devices in a storage array are not aware of a larger system in which they are embedded, or what the data means. Storage memory or storage devices in storage arrays can include various types of storage memory, such as RAM, solid state drives, hard disk drives, etc. The storage units 152 described herein have multiple interfaces active simultaneously and serving multiple purposes. In some embodiments, some of the functionality of a storage node 150 is shifted into a storage unit 152, transforming the storage unit 152 into a combination of storage unit 152 and storage node 150. Placing computing (relative to storage data) into the storage unit 152 places this computing closer to the data itself. The various system embodiments have a hierarchy of storage node layers with different capabilities. By contrast, in a storage array, a controller owns and knows everything about all of the data that the controller manages in a shelf or storage devices. In a storage cluster 161, as described herein, multiple controllers in multiple storage units 152 and/or storage nodes 150 cooperate in various ways (e.g., for erasure coding, data sharding, metadata communication and redundancy, storage capacity expansion or contraction, data recovery, and so on).

FIG. 2D shows a storage server environment, which uses embodiments of the storage nodes 150 and storage units 152 of FIGS. 2A-C. In this version, each storage unit 152 has a processor such as controller 212 (see FIG. 2C), an FPGA (field programmable gate array), flash memory 206, and NVRAM 204 (which is super-capacitor backed DRAM 216, see FIGS. 2B and 2C) on a PCIe (peripheral component interconnect express) board in a chassis 138 (see FIG. 2A). The storage unit 152 may be implemented as a single board containing storage, and may be the largest tolerable failure domain inside the chassis. In some embodiments, up to two storage units 152 may fail and the device will continue with no data loss.

The physical storage is divided into named regions based on application usage in some embodiments. The NVRAM 204 is a contiguous block of reserved memory in the storage unit 152 DRAM 216, and is backed by NAND flash. NVRAM 204 is logically divided into multiple memory regions written for two as spool (e.g., spool region). Space within the NVRAM 204 spools is managed by each authority 168 independently. Each device provides an amount of storage space to each authority 168. That authority 168 further manages lifetimes and allocations within that space. Examples of a spool include distributed transactions or notions. When the primary power to a storage unit 152 fails, onboard super-capacitors provide a short duration of power hold up. During this holdup interval, the contents of the NVRAM 204 are flushed to flash memory 206. On the next power-on, the contents of the NVRAM 204 are recovered from the flash memory 206.

As for the storage unit controller, the responsibility of the logical “controller” is distributed across each of the blades containing authorities 168. This distribution of logical control is shown in FIG. 2D as a host controller 242, mid-tier controller 244 and storage unit controller(s) 246. Management of the control plane and the storage plane are treated independently, although parts may be physically co-located on the same blade. Each authority 168 effectively serves as an independent controller. Each authority 168 provides its own data and metadata structures, its own background workers, and maintains its own lifecycle.

FIG. 2E is a blade 252 hardware block diagram, showing a control plane 254, compute and storage planes 256, 258, and authorities 168 interacting with underlying physical resources, using embodiments of the storage nodes 150 and storage units 152 of FIGS. 2A-C in the storage server environment of FIG. 2D. The control plane 254 is partitioned into a number of authorities 168 which can use the compute resources in the compute plane 256 to run on any of the blades 252. The storage plane 258 is partitioned into a set of devices, each of which provides access to flash 206 and NVRAM 204 resources. In one embodiment, the compute plane 256 may perform the operations of a storage array controller, as described herein, on one or more devices of the storage plane 258 (e.g., a storage array).

In the compute and storage planes 256, 258 of FIG. 2E, the authorities 168 interact with the underlying physical resources (i.e., devices). From the point of view of an authority 168, its resources are striped over all of the physical devices. From the point of view of a device, it provides resources to all authorities 168, irrespective of where the authorities happen to run. Each authority 168 has allocated or has been allocated one or more partitions 260 of storage memory in the storage units 152, e.g. partitions 260 in flash memory 206 and NVRAM 204. Each authority 168 uses those allocated partitions 260 that belong to it, for writing or reading user data. Authorities can be associated with differing amounts of physical storage of the system. For example, one authority 168 could have a larger number of partitions 260 or larger sized partitions 260 in one or more storage units 152 than one or more other authorities 168.

FIG. 2F depicts elasticity software layers in blades 252 of a storage cluster, in accordance with some embodiments. In the elasticity structure, elasticity software is symmetric, i.e., each blade's compute module 270 runs the three identical layers of processes depicted in FIG. 2F. Storage managers 274 execute read and write requests from other blades 252 for data and metadata stored in local storage unit 152 NVRAM 204 and flash 206. Authorities 168 fulfill client requests by issuing the necessary reads and writes to the blades 252 on whose storage units 152 the corresponding data or metadata resides. Endpoints 272 parse client connection requests received from switch fabric 146 supervisory software, relay the client connection requests to the authorities 168 responsible for fulfillment, and relay the authorities' 168 responses to clients. The symmetric three-layer structure enables the storage system's high degree of concurrency. Elasticity scales out efficiently and reliably in these embodiments. In addition, elasticity implements a unique scale-out technique that balances work evenly across all resources regardless of client access pattern, and maximizes concurrency by eliminating much of the need for inter-blade coordination that typically occurs with conventional distributed locking.

Still referring to FIG. 2F, authorities 168 running in the compute modules 270 of a blade 252 perform the internal operations required to fulfill client requests. One feature of elasticity is that authorities 168 are stateless, i.e., they cache active data and metadata in their own blades' 252 DRAMs for fast access, but the authorities store every update in their NVRAM 204 partitions on three separate blades 252 until the update has been written to flash 206. All the storage system writes to NVRAM 204 are in triplicate to partitions on three separate blades 252 in some embodiments. With triple-mirrored NVRAM 204 and persistent storage protected by parity and Reed-Solomon RAID checksums, the storage system can survive concurrent failure of two blades 252 with no loss of data, metadata, or access to either.

Because authorities 168 are stateless, they can migrate between blades 252. Each authority 168 has a unique identifier. NVRAM 204 and flash 206 partitions are associated with authorities' 168 identifiers, not with the blades 252 on which they are running in some. Thus, when an authority 168 migrates, the authority 168 continues to manage the same storage partitions from its new location. When a new blade 252 is installed in an embodiment of the storage cluster, the system automatically rebalances load by: partitioning the new blade's 252 storage for use by the system's authorities 168, migrating selected authorities 168 to the new blade 252, starting endpoints 272 on the new blade 252 and including them in the switch fabric's 146 client connection distribution algorithm.

From their new locations, migrated authorities 168 persist the contents of their NVRAM 204 partitions on flash 206, process read and write requests from other authorities 168, and fulfill the client requests that endpoints 272 direct to them. Similarly, if a blade 252 fails or is removed, the system redistributes its authorities 168 among the system's remaining blades 252. The redistributed authorities 168 continue to perform their original functions from their new locations.

FIG. 2G depicts authorities 168 and storage resources in blades 252 of a storage cluster, in accordance with some embodiments. Each authority 168 is exclusively responsible for a partition of the flash 206 and NVRAM 204 on each blade 252. The authority 168 manages the content and integrity of its partitions independently of other authorities 168. Authorities 168 compress incoming data and preserve it temporarily in their NVRAM 204 partitions, and then consolidate, RAID-protect, and persist the data in segments of the storage in their flash 206 partitions. As the authorities 168 write data to flash 206, storage managers 274 perform the necessary flash translation to optimize write performance and maximize media longevity. In the background, authorities 168 “garbage collect,” or reclaim space occupied by data that clients have made obsolete by overwriting the data. It should be appreciated that since authorities' 168 partitions are disjoint, there is no need for distributed locking to execute client and writes or to perform background functions.

The embodiments described herein may utilize various software, communication and/or networking protocols. In addition, the configuration of the hardware and/or software may be adjusted to accommodate various protocols. For example, the embodiments may utilize Active Directory, which is a database based system that provides authentication, directory, policy, and other services in a WINDOWS™ environment. In these embodiments, LDAP (Lightweight Directory Access Protocol) is one example application protocol for querying and modifying items in directory service providers such as Active Directory. In some embodiments, a network lock manager (‘NLM’) is utilized as a facility that works in cooperation with the Network File System (‘NFS’) to provide a System V style of advisory file and record locking over a network. The Server Message Block (‘SMB’) protocol, one version of which is also known as Common Internet File System (‘CIFS’), may be integrated with the storage systems discussed herein. SMP operates as an application-layer network protocol typically used for providing shared access to files, printers, and serial ports and miscellaneous communications between nodes on a network. SMB also provides an authenticated inter-process communication mechanism. AMAZON™ S3 (Simple Storage Service) is a web service offered by Amazon Web Services, and the systems described herein may interface with Amazon S3 through web services interfaces (REST (representational state transfer), SOAP (simple object access protocol), and BitTorrent). A RESTful API (application programming interface) breaks down a transaction to create a series of small modules. Each module addresses a particular underlying part of the transaction. The control or permissions provided with these embodiments, especially for object data, may include utilization of an access control list (‘ACL’). The ACL is a list of permissions attached to an object and the ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects. The systems may utilize Internet Protocol version 6 (‘IPv6’), as well as IPv4, for the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. The routing of packets between networked systems may include Equal-cost multi-path routing (‘ECMP’), which is a routing strategy where next-hop packet forwarding to a single destination can occur over multiple “best paths” which tie for top place in routing metric calculations. Multi-path routing can be used in conjunction with most routing protocols, because it is a per-hop decision limited to a single router. The software may support Multi-tenancy, which is an architecture in which a single instance of a software application serves multiple customers. Each customer may be referred to as a tenant. Tenants may be given the ability to customize some parts of the application, but may not customize the application's code, in some embodiments. The embodiments may maintain audit logs. An audit log is a document that records an event in a computing system. In addition to documenting what resources were accessed, audit log entries typically include destination and source addresses, a timestamp, and user login information for compliance with various regulations. The embodiments may support various key management policies, such as encryption key rotation. In addition, the system may support dynamic root passwords or some variation dynamically changing passwords.

FIG. 3A sets forth a diagram of a storage system 306 that is coupled for data communications with a cloud services provider 302 in accordance with some embodiments of the present disclosure. Although depicted in less detail, the storage system 306 depicted in FIG. 3A may be similar to the storage systems described above with reference to FIGS. 1A-1D and FIGS. 2A-2G. In some embodiments, the storage system 306 depicted in FIG. 3A may be embodied as a storage system that includes imbalanced active/active controllers, as a storage system that includes balanced active/active controllers, as a storage system that includes active/active controllers where less than all of each controller's resources are utilized such that each controller has reserve resources that may be used to support failover, as a storage system that includes fully active/active controllers, as a storage system that includes dataset-segregated controllers, as a storage system that includes dual-layer architectures with front-end controllers and back-end integrated storage controllers, as a storage system that includes scale-out clusters of dual-controller arrays, as well as combinations of such embodiments.

In the example depicted in FIG. 3A, the storage system 306 is coupled to the cloud services provider 302 via a data communications link 304. The data communications link 304 may be embodied as a dedicated data communications link, as a data communications pathway that is provided through the use of one or data communications networks such as a wide area network (‘WAN’) or local area network (‘LAN’), or as some other mechanism capable of transporting digital information between the storage system 306 and the cloud services provider 302. Such a data communications link 304 may be fully wired, fully wireless, or some aggregation of wired and wireless data communications pathways. In such an example, digital information may be exchanged between the storage system 306 and the cloud services provider 302 via the data communications link 304 using one or more data communications protocols. For example, digital information may be exchanged between the storage system 306 and the cloud services provider 302 via the data communications link 304 using the handheld device transfer protocol (‘HDTP’), hypertext transfer protocol (‘HTTP’), internet protocol (‘IP’), real-time transfer protocol (‘RTP’), transmission control protocol (‘TCP’), user datagram protocol (‘UDP’), wireless application protocol (‘WAP’), or other protocol.

The cloud services provider 302 depicted in FIG. 3A may be embodied, for example, as a system and computing environment that provides services to users of the cloud services provider 302 through the sharing of computing resources via the data communications link 304. The cloud services provider 302 may provide on-demand access to a shared pool of configurable computing resources such as computer networks, servers, storage, applications and services, and so on. The shared pool of configurable resources may be rapidly provisioned and released to a user of the cloud services provider 302 with minimal management effort. Generally, the user of the cloud services provider 302 is unaware of the exact computing resources utilized by the cloud services provider 302 to provide the services. Although in many cases such a cloud services provider 302 may be accessible via the Internet, readers of skill in the art will recognize that any system that abstracts the use of shared resources to provide services to a user through any data communications link may be considered a cloud services provider 302.

In the example depicted in FIG. 3A, the cloud services provider 302 may be configured to provide a variety of services to the storage system 306 and users of the storage system 306 through the implementation of various service models. For example, the cloud services provider 302 may be configured to provide services to the storage system 306 and users of the storage system 306 through the implementation of an infrastructure as a service (‘IaaS’) service model where the cloud services provider 302 offers computing infrastructure such as virtual machines and other resources as a service to subscribers. In addition, the cloud services provider 302 may be configured to provide services to the storage system 306 and users of the storage system 306 through the implementation of a platform as a service (‘PaaS’) service model where the cloud services provider 302 offers a development environment to application developers. Such a development environment may include, for example, an operating system, programming-language execution environment, database, web server, or other components that may be utilized by application developers to develop and run software solutions on a cloud platform. Furthermore, the cloud services provider 302 may be configured to provide services to the storage system 306 and users of the storage system 306 through the implementation of a software as a service (‘SaaS’) service model where the cloud services provider 302 offers application software, databases, as well as the platforms that are used to run the applications to the storage system 306 and users of the storage system 306, providing the storage system 306 and users of the storage system 306 with on-demand software and eliminating the need to install and run the application on local computers, which may simplify maintenance and support of the application. The cloud services provider 302 may be further configured to provide services to the storage system 306 and users of the storage system 306 through the implementation of an authentication as a service (‘AaaS’) service model where the cloud services provider 302 offers authentication services that can be used to secure access to applications, data sources, or other resources. The cloud services provider 302 may also be configured to provide services to the storage system 306 and users of the storage system 306 through the implementation of a storage as a service model where the cloud services provider 302 offers access to its storage infrastructure for use by the storage system 306 and users of the storage system 306. Readers will appreciate that the cloud services provider 302 may be configured to provide additional services to the storage system 306 and users of the storage system 306 through the implementation of additional service models, as the service models described above are included only for explanatory purposes and in no way represent a limitation of the services that may be offered by the cloud services provider 302 or a limitation as to the service models that may be implemented by the cloud services provider 302.

In the example depicted in FIG. 3A, the cloud services provider 302 may be embodied, for example, as a private cloud, as a public cloud, or as a combination of a private cloud and public cloud. In an embodiment in which the cloud services provider 302 is embodied as a private cloud, the cloud services provider 302 may be dedicated to providing services to a single organization rather than providing services to multiple organizations. In an embodiment where the cloud services provider 302 is embodied as a public cloud, the cloud services provider 302 may provide services to multiple organizations. Public cloud and private cloud deployment models may differ and may come with various advantages and disadvantages. For example, because a public cloud deployment involves the sharing of a computing infrastructure across different organization, such a deployment may not be ideal for organizations with security concerns, mission-critical workloads, uptime requirements demands, and so on. While a private cloud deployment can address some of these issues, a private cloud deployment may require on-premises staff to manage the private cloud. In still alternative embodiments, the cloud services provider 302 may be embodied as a mix of a private and public cloud services with a hybrid cloud deployment.

Although not explicitly depicted in FIG. 3A, readers will appreciate that additional hardware components and additional software components may be necessary to facilitate the delivery of cloud services to the storage system 306 and users of the storage system 306. For example, the storage system 306 may be coupled to (or even include) a cloud storage gateway. Such a cloud storage gateway may be embodied, for example, as hardware-based or software-based appliance that is located on premise with the storage system 306. Such a cloud storage gateway may operate as a bridge between local applications that are executing on the storage array 306 and remote, cloud-based storage that is utilized by the storage array 306. Through the use of a cloud storage gateway, organizations may move primary iSCSI or NAS to the cloud services provider 302, thereby enabling the organization to save space on their on-premises storage systems. Such a cloud storage gateway may be configured to emulate a disk array, a block-based device, a file server, or other storage system that can translate the SCSI commands, file server commands, or other appropriate command into REST-space protocols that facilitate communications with the cloud services provider 302.

In order to enable the storage system 306 and users of the storage system 306 to make use of the services provided by the cloud services provider 302, a cloud migration process may take place during which data, applications, or other elements from an organization's local systems (or even from another cloud environment) are moved to the cloud services provider 302. In order to successfully migrate data, applications, or other elements to the cloud services provider's 302 environment, middleware such as a cloud migration tool may be utilized to bridge gaps between the cloud services provider's 302 environment and an organization's environment. Such cloud migration tools may also be configured to address potentially high network costs and long transfer times associated with migrating large volumes of data to the cloud services provider 302, as well as addressing security concerns associated with sensitive data to the cloud services provider 302 over data communications networks. In order to further enable the storage system 306 and users of the storage system 306 to make use of the services provided by the cloud services provider 302, a cloud orchestrator may also be used to arrange and coordinate automated tasks in pursuit of creating a consolidated process or workflow. Such a cloud orchestrator may perform tasks such as configuring various components, whether those components are cloud components or on-premises components, as well as managing the interconnections between such components. The cloud orchestrator can simplify the inter-component communication and connections to ensure that links are correctly configured and maintained.

In the example depicted in FIG. 3A, and as described briefly above, the cloud services provider 302 may be configured to provide services to the storage system 306 and users of the storage system 306 through the usage of a SaaS service model where the cloud services provider 302 offers application software, databases, as well as the platforms that are used to run the applications to the storage system 306 and users of the storage system 306, providing the storage system 306 and users of the storage system 306 with on-demand software and eliminating the need to install and run the application on local computers, which may simplify maintenance and support of the application. Such applications may take many forms in accordance with various embodiments of the present disclosure. For example, the cloud services provider 302 may be configured to provide access to data analytics applications to the storage system 306 and users of the storage system 306. Such data analytics applications may be configured, for example, to receive telemetry data phoned home by the storage system 306. Such telemetry data may describe various operating characteristics of the storage system 306 and may be analyzed, for example, to determine the health of the storage system 306, to identify workloads that are executing on the storage system 306, to predict when the storage system 306 will run out of various resources, to recommend configuration changes, hardware or software upgrades, workflow migrations, or other actions that may improve the operation of the storage system 306.

The cloud services provider 302 may also be configured to provide access to virtualized computing environments to the storage system 306 and users of the storage system 306. Such virtualized computing environments may be embodied, for example, as a virtual machine or other virtualized computer hardware platforms, virtual storage devices, virtualized computer network resources, and so on. Examples of such virtualized environments can include virtual machines that are created to emulate an actual computer, virtualized desktop environments that separate a logical desktop from a physical machine, virtualized file systems that allow uniform access to different types of concrete file systems, and many others.

For further explanation, FIG. 3B sets forth a diagram of a storage system 306 in accordance with some embodiments of the present disclosure. Although depicted in less detail, the storage system 306 depicted in FIG. 3B may be similar to the storage systems described above with reference to FIGS. 1A-1D and FIGS. 2A-2G as the storage system may include many of the components described above.

The storage system 306 depicted in FIG. 3B may include storage resources 308, which may be embodied in many forms. For example, in some embodiments the storage resources 308 can include nano-RAM or another form of nonvolatile random access memory that utilizes carbon nanotubes deposited on a substrate. In some embodiments, the storage resources 308 may include 3D crosspoint non-volatile memory in which bit storage is based on a change of bulk resistance, in conjunction with a stackable cross-gridded data access array. In some embodiments, the storage resources 308 may include flash memory, including single-level cell (‘SLC’) NAND flash, multi-level cell (‘MLC’) NAND flash, triple-level cell (‘TLC’) NAND flash, quad-level cell (‘QLC’) NAND flash, and others. In some embodiments, the storage resources 308 may include non-volatile magnetoresistive random-access memory (‘MRAM’), including spin transfer torque (‘STT’) MRAM, in which data is stored through the use of magnetic storage elements. In some embodiments, the example storage resources 308 may include non-volatile phase-change memory (‘PCM’) that may have the ability to hold multiple bits in a single cell as cells can achieve a number of distinct intermediary states. In some embodiments, the storage resources 308 may include quantum memory that allows for the storage and retrieval of photonic quantum information. In some embodiments, the example storage resources 308 may include resistive random-access memory (‘ReRAM’) in which data is stored by changing the resistance across a dielectric solid-state material. In some embodiments, the storage resources 308 may include storage class memory (‘SCM’) in which solid-state nonvolatile memory may be manufactured at a high density using some combination of sub-lithographic patterning techniques, multiple bits per cell, multiple layers of devices, and so on. Readers will appreciate that other forms of computer memories and storage devices may be utilized by the storage systems described above, including DRAM, SRAM, EEPROM, universal memory, and many others. The storage resources 308 depicted in FIG. 3A may be embodied in a variety of form factors, including but not limited to, dual in-line memory modules (‘DIMMs’), non-volatile dual in-line memory modules (‘NVDIMMs’), M.2, U.2, and others.

The storage resources 308 depicted in FIG. 3A may include various forms of storage-class memory (‘SCM’). SCM may effectively treat fast, non-volatile memory (e.g., NAND flash) as an extension of DRAM such that an entire dataset may be treated as an in-memory dataset that resides entirely in DRAM. SCM may include non-volatile media such as, for example, NAND flash. Such NAND flash may be accessed utilizing NVMe that can use the PCIe bus as its transport, providing for relatively low access latencies compared to older protocols. In fact, the network protocols used for SSDs in all-flash arrays can include NVMe using Ethernet (ROCE, NVME TCP), Fibre Channel (NVMe FC), InfiniBand (iWARP), and others that make it possible to treat fast, non-volatile memory as an extension of DRAM. In view of the fact that DRAM is often byte-addressable and fast, non-volatile memory such as NAND flash is block-addressable, a controller software/hardware stack may be needed to convert the block data to the bytes that are stored in the media. Examples of media and software that may be used as SCM can include, for example, 3D XPoint, Intel Memory Drive Technology, Samsung's Z-SSD, and others.

The example storage system 306 depicted in FIG. 3B may implement a variety of storage architectures. For example, storage systems in accordance with some embodiments of the present disclosure may utilize block storage where data is stored in blocks, and each block essentially acts as an individual hard drive. Storage systems in accordance with some embodiments of the present disclosure may utilize object storage, where data is managed as objects. Each object may include the data itself, a variable amount of metadata, and a globally unique identifier, where object storage can be implemented at multiple levels (e.g., device level, system level, interface level). Storage systems in accordance with some embodiments of the present disclosure utilize file storage in which data is stored in a hierarchical structure. Such data may be saved in files and folders, and presented to both the system storing it and the system retrieving it in the same format.

The example storage system 306 depicted in FIG. 3B may be embodied as a storage system in which additional storage resources can be added through the use of a scale-up model, additional storage resources can be added through the use of a scale-out model, or through some combination thereof. In a scale-up model, additional storage may be added by adding additional storage devices. In a scale-out model, however, additional storage nodes may be added to a cluster of storage nodes, where such storage nodes can include additional processing resources, additional networking resources, and so on.

The storage system 306 depicted in FIG. 3B also includes communications resources 310 that may be useful in facilitating data communications between components within the storage system 306, as well as data communications between the storage system 306 and computing devices that are outside of the storage system 306. The communications resources 310 may be configured to utilize a variety of different protocols and data communication fabrics to facilitate data communications between components within the storage systems as well as computing devices that are outside of the storage system. For example, the communications resources 310 can include fibre channel (‘FC’) technologies such as FC fabrics and FC protocols that can transport SCSI commands over FC networks. The communications resources 310 can also include FC over ethernet (‘FCoE’) technologies through which FC frames are encapsulated and transmitted over Ethernet networks. The communications resources 310 can also include InfiniBand (‘IB’) technologies in which a switched fabric topology is utilized to facilitate transmissions between channel adapters. The communications resources 310 can also include NVM Express (‘NVMe’) technologies and NVMe over fabrics (‘NVMeoF’) technologies through which non-volatile storage media attached via a PCI express (‘PCIe’) bus may be accessed. The communications resources 310 can also include mechanisms for accessing storage resources 308 within the storage system 306 utilizing serial attached SCSI (‘SAS’), serial ATA (‘SATA’) bus interfaces for connecting storage resources 308 within the storage system 306 to host bus adapters within the storage system 306, internet small computer systems interface (‘iSCSI’) technologies to provide block-level access to storage resources 308 within the storage system 306, and other communications resources that that may be useful in facilitating data communications between components within the storage system 306, as well as data communications between the storage system 306 and computing devices that are outside of the storage system 306.

The storage system 306 depicted in FIG. 3B also includes processing resources 312 that may be useful in useful in executing computer program instructions and performing other computational tasks within the storage system 306. The processing resources 312 may include one or more application-specific integrated circuits (‘ASICs’) that are customized for some particular purpose as well as one or more central processing units (‘CPUs’). The processing resources 312 may also include one or more digital signal processors (‘DSPs’), one or more field-programmable gate arrays (‘FPGAs’), one or more systems on a chip (‘SoCs’), or other form of processing resources 312. The storage system 306 may utilize the storage resources 312 to perform a variety of tasks including, but not limited to, supporting the execution of software resources 314 that will be described in greater detail below.

The storage system 306 depicted in FIG. 3B also includes software resources 314 that, when executed by processing resources 312 within the storage system 306, may perform various tasks. The software resources 314 may include, for example, one or more modules of computer program instructions that when executed by processing resources 312 within the storage system 306 are useful in carrying out various data protection techniques to preserve the integrity of data that is stored within the storage systems. Readers will appreciate that such data protection techniques may be carried out, for example, by system software executing on computer hardware within the storage system, by a cloud services provider, or in other ways. Such data protection techniques can include, for example, data archiving techniques that cause data that is no longer actively used to be moved to a separate storage device or separate storage system for long-term retention, data backup techniques through which data stored in the storage system may be copied and stored in a distinct location to avoid data loss in the event of equipment failure or some other form of catastrophe with the storage system, data replication techniques through which data stored in the storage system is replicated to another storage system such that the data may be accessible via multiple storage systems, data snapshotting techniques through which the state of data within the storage system is captured at various points in time, data and database cloning techniques through which duplicate copies of data and databases may be created, and other data protection techniques. Through the use of such data protection techniques, business continuity and disaster recovery objectives may be met as a failure of the storage system may not result in the loss of data stored in the storage system.

The software resources 314 may also include software that is useful in implementing software-defined storage (‘SDS’). In such an example, the software resources 314 may include one or more modules of computer program instructions that, when executed, are useful in policy-based provisioning and management of data storage that is independent of the underlying hardware. Such software resources 314 may be useful in implementing storage virtualization to separate the storage hardware from the software that manages the storage hardware.

The software resources 314 may also include software that is useful in facilitating and optimizing I/O operations that are directed to the storage resources 308 in the storage system 306. For example, the software resources 314 may include software modules that perform carry out various data reduction techniques such as, for example, data compression, data deduplication, and others. The software resources 314 may include software modules that intelligently group together I/O operations to facilitate better usage of the underlying storage resource 308, software modules that perform data migration operations to migrate from within a storage system, as well as software modules that perform other functions. Such software resources 314 may be embodied as one or more software containers or in many other ways.

Readers will appreciate that the presence of such software resources 314 may provide for an improved user experience of the storage system 306, an expansion of functionality supported by the storage system 306, and many other benefits. Consider the specific example of the software resources 314 carrying out data backup techniques through which data stored in the storage system may be copied and stored in a distinct location to avoid data loss in the event of equipment failure or some other form of catastrophe. In such an example, the systems described herein may more reliably (and with less burden placed on the user) perform backup operations relative to interactive backup management systems that require high degrees of user interactivity, offer less robust automation and feature sets, and so on.

For further explanation, FIG. 3C sets forth an example of a cloud-based storage system 318 in accordance with some embodiments of the present disclosure. In the example depicted in FIG. 3C, the cloud-based storage system 318 is created entirely in a cloud computing environment 316 such as, for example, Amazon Web Services (‘AWS’), Microsoft Azure, Google Cloud Platform, IBM Cloud, Oracle Cloud, and others. The cloud-based storage system 318 may be used to provide services similar to the services that may be provided by the storage systems described above. For example, the cloud-based storage system 318 may be used to provide block storage services to users of the cloud-based storage system 318, the cloud-based storage system 318 may be used to provide storage services to users of the cloud-based storage system 318 through the use of solid-state storage, and so on.

The cloud-based storage system 318 depicted in FIG. 3C includes two cloud computing instances 320, 322 that each are used to support the execution of a storage controller application 324, 326. The cloud computing instances 320, 322 may be embodied, for example, as instances of cloud computing resources (e.g., virtual machines) that may be provided by the cloud computing environment 316 to support the execution of software applications such as the storage controller application 324, 326. In one embodiment, the cloud computing instances 320, 322 may be embodied as Amazon Elastic Compute Cloud (‘EC2’) instances. In such an example, an Amazon Machine Image (‘AMI’) that includes the storage controller application 324, 326 may be booted to create and configure a virtual machine that may execute the storage controller application 324, 326. In other embodiments, the cloud computing instances 320 may be embodied as virtual machines in Microsoft Azure, as instances of Amazon's EC2 container service (ECS), as Azure Container Instances, or in many other ways.

In the example method depicted in FIG. 3C, the storage controller application 324, 326 may be embodied as a module of computer program instructions that, when executed, carries out various storage tasks. For example, the storage controller application 324, 326 may be embodied as a module of computer program instructions that, when executed, carries out the same tasks as the controllers 110A, 110B in FIG. 1A described above such as writing data received from the users of the cloud-based storage system 318 to the cloud-based storage system 318, erasing data from the cloud-based storage system 318, retrieving data from the cloud-based storage system 318 and providing such data to users of the cloud-based storage system 318, monitoring and reporting of disk utilization and performance, performing redundancy operations, such as RAID or RAID-like data redundancy operations, compressing data, encrypting data, deduplicating data, and so forth. Readers will appreciate that because there are two cloud computing instances 320, 322 that each include the storage controller application 324, 326, in some embodiments one cloud computing instance 320 may operate as the primary controller as described above while the other cloud computing instance 322 may operate as the secondary controller as described above. In such an example, in order to save costs, the cloud computing instance 320 that operates as the primary controller may be deployed on a relatively high-performance and relatively expensive cloud computing instance while the cloud computing instance 322 that operates as the secondary controller may be deployed on a relatively low-performance and relatively inexpensive cloud computing instance. Readers will appreciate that the storage controller application 324, 326 depicted in FIG. 3C may include identical source code that is executed within different cloud computing instances 320, 322.

Consider an example in which the cloud computing environment 316 is embodied as AWS and the cloud computing instances are embodied as EC2 instances. In such an example, AWS offers many types of EC2 instances. For example, AWS offers a suite of general purpose EC2 instances that include varying levels of memory and processing power. In such an example, the cloud computing instance 320 that operates as the primary controller may be deployed on one of the instance types that has a relatively large amount of memory and processing power while the cloud computing instance 322 that operates as the secondary controller may be deployed on one of the instance types that has a relatively small amount of memory and processing power. In such an example, upon the occurrence of a failover event where the roles of primary and secondary are switched, a double failover may actually be carried out such that: 1) a first failover event where the cloud computing instance 322 that formerly operated as the secondary controller begins to operate as the primary controller, and 2) a third cloud computing instance (not shown) that is of an instance type that has a relatively large amount of memory and processing power is spun up with a copy of the storage controller application, where the third cloud computing instance begins operating as the primary controller while the cloud computing instance 322 that originally operated as the secondary controller begins operating as the secondary controller again. In such an example, the cloud computing instance 320 that formerly operated as the primary controller may be terminated. Readers will appreciate that in alternative embodiments, the cloud computing instance 320 that is operating as the secondary controller after the failover event may continue to operate as the secondary controller and the cloud computing instance 322 that operated as the primary controller after the occurrence of the failover event may be terminated once the primary role has been assumed by the third cloud computing instance (not shown).

Readers will appreciate that while the embodiments described above relate to embodiments where one cloud computing instance 320 operates as the primary controller and the second cloud computing instance 322 operates as the secondary controller, some embodiments are within the scope of the present disclosure. For example, each cloud computing instance 320, 322 may operate as a primary controller for some portion of the address space supported by the cloud-based storage system 318, each cloud computing instance 320, 322 may operate as a primary controller where the servicing of I/O operations directed to the cloud-based storage system 318 are divided in some other way, and so on. In fact, in some embodiments where costs savings may be prioritized over performance demands, only a single cloud computing instance may exist that contains the storage controller application. In such an example, a controller failure may take more time to recover from as a new cloud computing instance that includes the storage controller application would need to be spun up rather than having an already created cloud computing instance take on the role of servicing I/O operations that would have otherwise been handled by the failed cloud computing instance.

The cloud-based storage system 318 depicted in FIG. 3C includes cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338. The cloud computing instances 340 a, 340 b, 340 n depicted in FIG. 3C may be embodied, for example, as instances of cloud computing resources that may be provided by the cloud computing environment 316 to support the execution of software applications. The cloud computing instances 340 a, 340 b, 340 n of FIG. 3C may differ from the cloud computing instances 320, 322 described above as the cloud computing instances 340 a, 340 b, 340 n of FIG. 3C have local storage 330, 334, 338 resources whereas the cloud computing instances 320, 322 that support the execution of the storage controller application 324, 326 need not have local storage resources. The cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 may be embodied, for example, as EC2 M5 instances that include one or more SSDs, as EC2 R5 instances that include one or more SSDs, as EC2 I3 instances that include one or more SSDs, and so on. In some embodiments, the local storage 330, 334, 338 must be embodied as solid-state storage (e.g., SSDs) rather than storage that makes use of hard disk drives.

In the example depicted in FIG. 3C, each of the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 can include a software daemon 328, 332, 336 that, when executed by a cloud computing instance 340 a, 340 b, 340 n can present itself to the storage controller applications 324, 326 as if the cloud computing instance 340 a, 340 b, 340 n were a physical storage device (e.g., one or more SSDs). In such an example, the software daemon 328, 332, 336 may include computer program instructions similar to those that would normally be contained on a storage device such that the storage controller applications 324, 326 can send and receive the same commands that a storage controller would send to storage devices. In such a way, the storage controller applications 324, 326 may include code that is identical to (or substantially identical to) the code that would be executed by the controllers in the storage systems described above. In these and similar embodiments, communications between the storage controller applications 324, 326 and the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 may utilize iSCSI, NVMe over TCP, messaging, a custom protocol, or in some other mechanism.

In the example depicted in FIG. 3C, each of the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 may also be coupled to block-storage 342, 344, 346 that is offered by the cloud computing environment 316. The block-storage 342, 344, 346 that is offered by the cloud computing environment 316 may be embodied, for example, as Amazon Elastic Block Store (‘EBS’) volumes. For example, a first EBS volume may be coupled to a first cloud computing instance 340 a, a second EBS volume may be coupled to a second cloud computing instance 340 b, and a third EBS volume may be coupled to a third cloud computing instance 340 n. In such an example, the block-storage 342, 344, 346 that is offered by the cloud computing environment 316 may be utilized in a manner that is similar to how the NVRAM devices described above are utilized, as the software daemon 328, 332, 336 (or some other module) that is executing within a particular cloud comping instance 340 a, 340 b, 340 n may, upon receiving a request to write data, initiate a write of the data to its attached EBS volume as well as a write of the data to its local storage 330, 334, 338 resources. In some alternative embodiments, data may only be written to the local storage 330, 334, 338 resources within a particular cloud comping instance 340 a, 340 b, 340 n. In an alternative embodiment, rather than using the block-storage 342, 344, 346 that is offered by the cloud computing environment 316 as NVRAM, actual RAM on each of the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 may be used as NVRAM, thereby decreasing network utilization costs that would be associated with using an EBS volume as the NVRAM.

In the example depicted in FIG. 3C, the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 may be utilized, by cloud computing instances 320, 322 that support the execution of the storage controller application 324, 326 to service I/O operations that are directed to the cloud-based storage system 318. Consider an example in which a first cloud computing instance 320 that is executing the storage controller application 324 is operating as the primary controller. In such an example, the first cloud computing instance 320 that is executing the storage controller application 324 may receive (directly or indirectly via the secondary controller) requests to write data to the cloud-based storage system 318 from users of the cloud-based storage system 318. In such an example, the first cloud computing instance 320 that is executing the storage controller application 324 may perform various tasks such as, for example, deduplicating the data contained in the request, compressing the data contained in the request, determining where to the write the data contained in the request, and so on, before ultimately sending a request to write a deduplicated, encrypted, or otherwise possibly updated version of the data to one or more of the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338. Either cloud computing instance 320, 322, in some embodiments, may receive a request to read data from the cloud-based storage system 318 and may ultimately send a request to read data to one or more of the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338.

Readers will appreciate that when a request to write data is received by a particular cloud computing instance 340 a, 340 b, 340 n with local storage 330, 334, 338, the software daemon 328, 332, 336 or some other module of computer program instructions that is executing on the particular cloud computing instance 340 a, 340 b, 340 n may be configured to not only write the data to its own local storage 330, 334, 338 resources and any appropriate block-storage 342, 344, 346 that are offered by the cloud computing environment 316, but the software daemon 328, 332, 336 or some other module of computer program instructions that is executing on the particular cloud computing instance 340 a, 340 b, 340 n may also be configured to write the data to cloud-based object storage 348 that is attached to the particular cloud computing instance 340 a, 340 b, 340 n. The cloud-based object storage 348 that is attached to the particular cloud computing instance 340 a, 340 b, 340 n may be embodied, for example, as Amazon Simple Storage Service (‘S3’) storage that is accessible by the particular cloud computing instance 340 a, 340 b, 340 n. In some embodiments, the cloud computing instances 320, 322 that each include the storage controller application 324, 326 may initiate the storage of the data in the local storage 330, 334, 338 of the cloud computing instances 340 a, 340 b, 340 n and the cloud-based object storage 348.

Readers will appreciate that, as described above, the cloud-based storage system 318 may be used to provide block storage services to users of the cloud-based storage system 318. While the local storage 330, 334, 338 resources and the block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n may support block-level access, the cloud-based object storage 348 that is attached to the particular cloud computing instance 340 a, 340 b, 340 n supports only object-based access. In order to address this, the software daemon 328, 332, 336 or some other module of computer program instructions that is executing on the particular cloud computing instance 340 a, 340 b, 340 n may be configured to take blocks of data, package those blocks into objects, and write the objects to the cloud-based object storage 348 that is attached to the particular cloud computing instance 340 a, 340 b, 340 n.

Consider an example in which data is written to the local storage 330, 334, 338 resources and the block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n in 1 MB blocks. In such an example, assume that a user of the cloud-based storage system 318 issues a request to write data that, after being compressed and deduplicated by the storage controller application 324, 326 results in the need to write 5 MB of data. In such an example, writing the data to the local storage 330, 334, 338 resources and the block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n is relatively straightforward as 5 blocks that are 1 MB in size are written to the local storage 330, 334, 338 resources and the block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n. In such an example, the software daemon 328, 332, 336 or some other module of computer program instructions that is executing on the particular cloud computing instance 340 a, 340 b, 340 n may be configured to: 1) create a first object that includes the first 1 MB of data and write the first object to the cloud-based object storage 348, 2) create a second object that includes the second 1 MB of data and write the second object to the cloud-based object storage 348, 3) create a third object that includes the third 1 MB of data and write the third object to the cloud-based object storage 348, and so on. As such, in some embodiments, each object that is written to the cloud-based object storage 348 may be identical (or nearly identical) in size. Readers will appreciate that in such an example, metadata that is associated with the data itself may be included in each object (e.g., the first 1 MB of the object is data and the remaining portion is metadata associated with the data).

Readers will appreciate that the cloud-based object storage 348 may be incorporated into the cloud-based storage system 318 to increase the durability of the cloud-based storage system 318. Continuing with the example described above where the cloud computing instances 340 a, 340 b, 340 n are EC2 instances, readers will understand that EC2 instances are only guaranteed to have a monthly uptime of 99.9% and data stored in the local instance store only persists during the lifetime of the EC2 instance. As such, relying on the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 as the only source of persistent data storage in the cloud-based storage system 318 may result in a relatively unreliable storage system. Likewise, EBS volumes are designed for 99.999% availability. As such, even relying on EBS as the persistent data store in the cloud-based storage system 318 may result in a storage system that is not sufficiently durable. Amazon S3, however, is designed to provide 99.9999999999% durability, meaning that a cloud-based storage system 318 that can incorporate S3 into its pool of storage is substantially more durable than various other options.

Readers will appreciate that while a cloud-based storage system 318 that can incorporate S3 into its pool of storage is substantially more durable than various other options, utilizing S3 as the primary pool of storage may result in storage system that has relatively slow response times and relatively long I/O latencies. As such, the cloud-based storage system 318 depicted in FIG. 3C not only stores data in S3 but the cloud-based storage system 318 also stores data in local storage 330, 334, 338 resources and block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n, such that read operations can be serviced from local storage 330, 334, 338 resources and the block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n, thereby reducing read latency when users of the cloud-based storage system 318 attempt to read data from the cloud-based storage system 318.

In some embodiments, all data that is stored by the cloud-based storage system 318 may be stored in both: 1) the cloud-based object storage 348, and 2) at least one of the local storage 330, 334, 338 resources or block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n. In such embodiments, the local storage 330, 334, 338 resources and block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n may effectively operate as cache that generally includes all data that is also stored in S3, such that all reads of data may be serviced by the cloud computing instances 340 a, 340 b, 340 n without requiring the cloud computing instances 340 a, 340 b, 340 n to access the cloud-based object storage 348. Readers will appreciate that in some embodiments, however, all data that is stored by the cloud-based storage system 318 may be stored in the cloud-based object storage 348, but less than all data that is stored by the cloud-based storage system 318 may be stored in at least one of the local storage 330, 334, 338 resources or block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n. In such an example, various policies may be utilized to determine which subset of the data that is stored by the cloud-based storage system 318 should reside in both: 1) the cloud-based object storage 348, and 2) at least one of the local storage 330, 334, 338 resources or block-storage 342, 344, 346 resources that are utilized by the cloud computing instances 340 a, 340 b, 340 n.

As described above, when the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 are embodied as EC2 instances, the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 are only guaranteed to have a monthly uptime of 99.9% and data stored in the local instance store only persists during the lifetime of each cloud computing instance 340 a, 340 b, 340 n with local storage 330, 334, 338. As such, one or more modules of computer program instructions that are executing within the cloud-based storage system 318 (e.g., a monitoring module that is executing on its own EC2 instance) may be designed to handle the failure of one or more of the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338. In such an example, the monitoring module may handle the failure of one or more of the cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 by creating one or more new cloud computing instances with local storage, retrieving data that was stored on the failed cloud computing instances 340 a, 340 b, 340 n from the cloud-based object storage 348, and storing the data retrieved from the cloud-based object storage 348 in local storage on the newly created cloud computing instances. Readers will appreciate that many variants of this process may be implemented.

Consider an example in which all cloud computing instances 340 a, 340 b, 340 n with local storage 330, 334, 338 failed. In such an example, the monitoring module may create new cloud computing instances with local storage, where high-bandwidth instances types are selected that allow for the maximum data transfer rates between the newly created high-bandwidth cloud computing instances with local storage and the cloud-based object storage 348. Readers will appreciate that instances types are selected that allow for the maximum data transfer rates between the new cloud computing instances and the cloud-based object storage 348 such that the new high-bandwidth cloud computing instances can be rehydrated with data from the cloud-based object storage 348 as quickly as possible. Once the new high-bandwidth cloud computing instances are rehydrated with data from the cloud-based object storage 348, less expensive lower-bandwidth cloud computing instances may be created, data may be migrated to the less expensive lower-bandwidth cloud computing instances, and the high-bandwidth cloud computing instances may be terminated.

Readers will appreciate that in some embodiments, the number of new cloud computing instances that are created may substantially exceed the number of cloud computing instances that are needed to locally store all of the data stored by the cloud-based storage system 318. The number of new cloud computing instances that are created may substantially exceed the number of cloud computing instances that are needed to locally store all of the data stored by the cloud-based storage system 318 in order to more rapidly pull data from the cloud-based object storage 348 and into the new cloud computing instances, as each new cloud computing instance can (in parallel) retrieve some portion of the data stored by the cloud-based storage system 318. In such embodiments, once the data stored by the cloud-based storage system 318 has been pulled into the newly created cloud computing instances, the data may be consolidated within a subset of the newly created cloud computing instances and those newly created cloud computing instances that are excessive may be terminated.

Consider an example in which 1000 cloud computing instances are needed in order to locally store all valid data that users of the cloud-based storage system 318 have written to the cloud-based storage system 318. In such an example, assume that all 1,000 cloud computing instances fail. In such an example, the monitoring module may cause 100,000 cloud computing instances to be created, where each cloud computing instance is responsible for retrieving, from the cloud-based object storage 348, distinct 1/100,000th chunks of the valid data that users of the cloud-based storage system 318 have written to the cloud-based storage system 318 and locally storing the distinct chunk of the dataset that it retrieved. In such an example, because each of the 100,000 cloud computing instances can retrieve data from the cloud-based object storage 348 in parallel, the caching layer may be restored 100 times faster as compared to an embodiment where the monitoring module only create 1000 replacement cloud computing instances. In such an example, over time the data that is stored locally in the 100,000 could be consolidated into 1,000 cloud computing instances and the remaining 99,000 cloud computing instances could be terminated.

Readers will appreciate that various performance aspects of the cloud-based storage system 318 may be monitored (e.g., by a monitoring module that is executing in an EC2 instance) such that the cloud-based storage system 318 can be scaled-up or scaled-out as needed. Consider an example in which the monitoring module monitors the performance of the could-based storage system 318 via communications with one or more of the cloud computing instances 320, 322 that each are used to support the execution of a storage controller application 324, 326, via monitoring communications between cloud computing instances 320, 322, 340 a, 340 b, 340 n, via monitoring communications between cloud computing instances 320, 322, 340 a, 340 b, 340 n and the cloud-based object storage 348, or in some other way. In such an example, assume that the monitoring module determines that the cloud computing instances 320, 322 that are used to support the execution of a storage controller application 324, 326 are undersized and not sufficiently servicing the I/O requests that are issued by users of the cloud-based storage system 318. In such an example, the monitoring module may create a new, more powerful cloud computing instance (e.g., a cloud computing instance of a type that includes more processing power, more memory, etc. . . . ) that includes the storage controller application such that the new, more powerful cloud computing instance can begin operating as the primary controller. Likewise, if the monitoring module determines that the cloud computing instances 320, 322 that are used to support the execution of a storage controller application 324, 326 are oversized and that cost savings could be gained by switching to a smaller, less powerful cloud computing instance, the monitoring module may create a new, less powerful (and less expensive) cloud computing instance that includes the storage controller application such that the new, less powerful cloud computing instance can begin operating as the primary controller.

Consider, as an additional example of dynamically sizing the cloud-based storage system 318, an example in which the monitoring module determines that the utilization of the local storage that is collectively provided by the cloud computing instances 340 a, 340 b, 340 n has reached a predetermined utilization threshold (e.g., 95%). In such an example, the monitoring module may create additional cloud computing instances with local storage to expand the pool of local storage that is offered by the cloud computing instances. Alternatively, the monitoring module may create one or more new cloud computing instances that have larger amounts of local storage than the already existing cloud computing instances 340 a, 340 b, 340 n, such that data stored in an already existing cloud computing instance 340 a, 340 b, 340 n can be migrated to the one or more new cloud computing instances and the already existing cloud computing instance 340 a, 340 b, 340 n can be terminated, thereby expanding the pool of local storage that is offered by the cloud computing instances. Likewise, if the pool of local storage that is offered by the cloud computing instances is unnecessarily large, data can be consolidated and some cloud computing instances can be terminated.

Readers will appreciate that the cloud-based storage system 318 may be sized up and down automatically by a monitoring module applying a predetermined set of rules that may be relatively simple of relatively complicated. In fact, the monitoring module may not only take into account the current state of the cloud-based storage system 318, but the monitoring module may also apply predictive policies that are based on, for example, observed behavior (e.g., every night from 10 PM until 6 AM usage of the storage system is relatively light), predetermined fingerprints (e.g., every time a virtual desktop infrastructure adds 100 virtual desktops, the number of IOPS directed to the storage system increase by X), and so on. In such an example, the dynamic scaling of the cloud-based storage system 318 may be based on current performance metrics, predicted workloads, and many other factors, including combinations thereof.

Readers will further appreciate that because the cloud-based storage system 318 may be dynamically scaled, the cloud-based storage system 318 may even operate in a way that is more dynamic. Consider the example of garbage collection. In a traditional storage system, the amount of storage is fixed. As such, at some point the storage system may be forced to perform garbage collection as the amount of available storage has become so constrained that the storage system is on the verge of running out of storage. In contrast, the cloud-based storage system 318 described here can always ‘add’ additional storage (e.g., by adding more cloud computing instances with local storage). Because the cloud-based storage system 318 described here can always ‘add’ additional storage, the cloud-based storage system 318 can make more intelligent decisions regarding when to perform garbage collection. For example, the cloud-based storage system 318 may implement a policy that garbage collection only be performed when the number of IOPS being serviced by the cloud-based storage system 318 falls below a certain level. In some embodiments, other system-level functions (e.g., deduplication, compression) may also be turned off and on in response to system load, given that the size of the cloud-based storage system 318 is not constrained in the same way that traditional storage systems are constrained.

Readers will appreciate that embodiments of the present disclosure resolve an issue with block-storage services offered by some cloud computing environments as some cloud computing environments only allow for one cloud computing instance to connect to a block-storage volume at a single time. For example, in Amazon AWS, only a single EC2 instance may be connected to an EBS volume. Through the use of EC2 instances with local storage, embodiments of the present disclosure can offer multi-connect capabilities where multiple EC2 instances can connect to another EC2 instance with local storage (‘a drive instance’). In such embodiments, the drive instances may include software executing within the drive instance that allows the drive instance to support I/O directed to a particular volume from each connected EC2 instance. As such, some embodiments of the present disclosure may be embodied as multi-connect block storage services that may not include all of the components depicted in FIG. 3C.

In some embodiments, especially in embodiments where the cloud-based object storage 348 resources are embodied as Amazon S3, the cloud-based storage system 318 may include one or more modules (e.g., a module of computer program instructions executing on an EC2 instance) that are configured to ensure that when the local storage of a particular cloud computing instance is rehydrated with data from S3, the appropriate data is actually in S3. This issue arises largely because S3 implements an eventual consistency model where, when overwriting an existing object, reads of the object will eventually (but not necessarily immediately) become consistent and will eventually (but not necessarily immediately) return the overwritten version of the object. To address this issue, in some embodiments of the present disclosure, objects in S3 are never overwritten. Instead, a traditional ‘overwrite’ would result in the creation of the new object (that includes the updated version of the data) and the eventual deletion of the old object (that includes the previous version of the data).

In some embodiments of the present disclosure, as part of an attempt to never (or almost never) overwrite an object, when data is written to S3 the resultant object may be tagged with a sequence number. In some embodiments, these sequence numbers may be persisted elsewhere (e.g., in a database) such that at any point in time, the sequence number associated with the most up-to-date version of some piece of data can be known. In such a way, a determination can be made as to whether S3 has the most recent version of some piece of data by merely reading the sequence number associated with an object—and without actually reading the data from S3. The ability to make this determination may be particularly important when a cloud computing instance with local storage crashes, as it would be undesirable to rehydrate the local storage of a replacement cloud computing instance with out-of-date data. In fact, because the cloud-based storage system 318 does not need to access the data to verify its validity, the data can stay encrypted and access charges can be avoided.

For further explanation, FIG. 3D sets forth a block diagram illustrating an example cloud-based storage system (366) (occasionally referred to hereafter as a ‘virtual storage system’) in accordance with some embodiments of the present disclosure. Adapting a physical storage system implementation to run in typical cloud infrastructure, such as a cloud computing environment (364) depicted herein, can be accomplished by providing a place to run the software that implements the storage system on one or more storage system controllers, providing suitable replacements for the hardware components that the storage system software would normally interact with, and adapting the high availability (‘HA’) models used to keep the storage system running in the case of failures or that keep it from losing data in the face of transient failures that exceed what the storage system can tolerate and keep running.

For context, this collection of descriptions relates to operation within the set of available advertised constructs typical to cloud-based Infrastructure as a Service (‘IaaS’) platforms, roughly as that style of cloud infrastructure is defined by Amazon Web Services, Microsoft Azure, Google Cloud Platform, and others. Typical available constructs, and their characteristics, within such cloud platforms include:

-   -   Compute instances, typically running as virtual machines         flexibly allocated to physical host servers.     -   A division of resources into separate geographic regions which         have faster and higher-bandwidth access to users, non-cloud         resources, and other cloud platform components within the same         geographic region.     -   A division of resources within geographic regions into zones         with separate survivability in cases of wide-scale data center         failures, network failures, power grid failures, administrative         mistakes, and so on. Resources within a particular cloud         platform that are in separate survivability zones within the         same geographic region generally have fairly high bandwidth and         reasonably low latency between each other.     -   Local instance storage, as hard drives or solid-state drives, or         as rack-local storage systems, providing private storage to a         compute instance. These are not necessarily intended for very         long-term use, can't be migrated as virtual machines migrate         between host systems, can't be shared between virtual machines,         and come with few durability guarantees due to their local         nature. These are typically reasonably inexpensive and are not         billed based on I/Os issued against them.     -   Relatively high-speed reasonably durable block stores which can         often be connected to only one virtual machine at a time, but         whose access can be migrated. An example of this is EBS in AWS.     -   Object stores, typically Amazon S3 or a protocol derived from         S3, which are very durable, surviving wide-spread outages         through inter-survivability zone and cross-geography         replication. Objects are easy to create (as a web service PUT         operation to create an object with a name within some bucket         associated with an account) and to retrieve, as a web service         GET operation), and parallel creates and retrievals across a         sufficient number of objects can yield enormous bandwidth. But         latency is very poor, and modifications or replacement of         objects complete in unpredictable amounts of time. Also,         availability, as opposed to durability, of object stores is         often not that great, though that is an issue with many services         running in cloud environments.     -   A variety of databases, including high-scale key-value store         databases with reasonable durability (similar to the high-speed         durable block stores) and convenient sets of atomic update         primitives. This disclosure frequently refers to one of these,         DynamoDB, which is a simple highly durable key/value store with         convenient atomic update primitives.

The elements of a virtual storage system (i.e., a cloud-based storage system (366)) from the context of this disclosure will each be expanded upon later. In many embodiments, the following minimal set of components and concepts for constructing and defining a virtual storage system built on a cloud platform, as an analog to a more traditional physical storage system, can include:

-   -   Virtual storage system controllers, depicted in FIG. 3D as an         active storage system virtual controller compute instance (368)         and a standby active storage system virtual controller compute         instance (370). The virtual storage system controllers may be         running on compute instances somewhere within the cloud         platform's infrastructure. The virtual storage system         controllers could be running, for example, on virtual machines,         in containers, or on bare metal servers. The virtual storage         system controllers run the core storage system logic, taking in         I/O and configuration requests from client hosts (possibly         through intermediary servers, not shown here) or from         administrative interfaces or tools, and then configuring and         implementing the unique capabilities of the particular storage         system, including implementing, but not limited to, core file         system, block services, or object storage logic (for storage         systems that present file systems, block-based volumes, or         object stores to host clients), snapshots, replication,         migration services, provisioning, host connectivity management,         deduplication, compression, and so on. The virtual storage         system controllers are also referred to herein as         cloud-computing instances that are used to support the execution         of the storage controller application, storage system virtual         controller compute instances, local instance storage, virtual         controllers, and the like.     -   Virtual drives (372, 376, 380, 384), running on compute         instances, referred to herein as virtual storage device servers,         that present storage out of available components presented by         the cloud platform. A virtual drive represents something similar         to a storage device, such as a disk drive or solid-state drive,         within the context of a traditional physical storage system,         from the standpoint of the virtual storage system architecture         and implementation. The virtual drives are also referred to         herein as cloud computing instances with local storage, VDrives,         and the like.     -   A virtual storage system dataset. This is a defined collection         of data and metadata that represents coherently managed content         representing a collection of file systems, volumes, objects, and         so on.     -   Segments. These are medium sized chunks of data, for example in         the range of 1 megabyte to 64 megabytes, that hold some         combination of data and metadata that is written together as a         unit to storage. The virtual storage system may combine data and         metadata together into segments in a variety of ways, though         some descriptions reference parity segments, which are segments         that store calculated parity content based on an erasure code         (e.g., RAID-5 P and Q data) computed from the content of other         segments.

In the example depicted in FIG. 3D, other components include instance stores for volumes (374, 378, 382, 386), EBS NVRAM (388, 390), a DynamoDB member table (396), a DynamoDB segment seq # table (394), as will be explained in greater detail below. The actual boundaries between virtual storage system controllers and the virtual drive servers that host virtual drives can be flexible. Implementations could merge these together to support a scale-out storage system, for example. Since the virtual drive servers are themselves support general purpose compute, the model lends itself to functions migrating between virtual storage system controllers and virtual drive servers, or lend themselves to other kinds of optimizations that are less common for traditional physical storage devices which may well include a general purpose CPU but where that general purpose CPU is generally quite low powered and lacking in RAM for handling complex in-memory calculations.

The term virtual storage system logic may be used herein to generalize the concept of the distributed programming that implements the core logic of the storage system, however that logic is distributed between virtual storage system controllers, scale-out implementations that combine virtual storage system controllers and virtual drive servers, and implementations that split or otherwise optimize processing between the virtual storage system controllers and the virtual drive servers.

Implementing a highly available and reasonably high capacity storage system using a cloud platform should take into account the capabilities and limitations of readily available cloud platform components which are quite different from hardware components used in a physical storage system. There are block-based storage capabilities implemented within cloud platforms, such as Elastic Block Store, which could be used in place of disk drives. These are expensive to use, though, are often billed based on I/O traffic as well as capacity, and often don't support concurrent sharing between compute instances, all of which limits their practicality in creating highly available infrastructure that can survive compute instance failure by switching to another compute instance or that can scale better by running storage system controller software concurrently in several compute instances using the same back-end block storage.

Local instance storage, such as the cloud computing instances with local storage that are described above, is more practical from a cost standpoint but becomes unavailable if the physical host it is attached to fails, and it can't be reattached to an alternate host if the failure is persistent. Local instance storage can be used to implement a virtual storage device (e.g., the VDrives depicted in FIG. 3D) that can be shared to other compute instances that run storage system controller software. That way, RAID-style software running in the storage system controller compute instances can be used to tolerate failures of the compute instances connected directly to instance storage that implement storage devices.

For local instance storage to be cost effective on a per-byte basis virtual storage “device server” compute instances might be attached to a few dozen to a few hundred terabytes, which is substantially larger than current physical storage devices. This could mean that the minimum size for, say, a cost effective 6+2 RAID-6 storage system could be several hundred terabytes to nearly a petabyte. To offset this, such a virtual device server might provide several “virtual drives” to several virtual storage systems. Tolerating survivability zone failures can be challenging, though, since geographic regions don't usually have enough of them for effective erasure coding between them and crossing geographic regions has substantial latency costs. Mirroring between survivability zones can work at a capacity cost.

Object storage, such as the S3 bucket (392) depicted in FIG. 3D (although other object storage such as Azure blob storage could be used), is by far the most durable form of at-scale storage available within current cloud platforms. It has availability issues, but the probability of data being lost or corrupted is exceedingly low. It has long (and somewhat unpredictable) latencies, though, making it poorly suited as the only storage for virtual storage systems that require something closer to the performance characteristics of physical storage systems. With enough parallel operations, data can be stored into and retrieved from object storage with very high bandwidth.

One way to make suitable storage devices with suitable performance, durability, and reliability for a virtual cloud-implemented storage system is to get performance from instance storage (e.g., the VDrives/cloud computing instances with local storage described previously) and durability from object storage. In this model, a compute instance with a local instance store implements a storage device, but content is also written to object stores. The local instance store operates either as a cache or as a complete copy of the data written to object stores. Unfortunately, the high (and unpredictable) write latency for writing objects makes it impractical for the object store to contain all recently written and acknowledged modifications to the storage system content. As a result, the very high durability of object stores can't quite be leveraged for zero RPO (recovery point objective) recoverable content if a goal is reasonably low-latency storage for the virtual storage system, as will be addressed in greater detail below.

An interesting point of similarity between optimizing a storage system for flash storage and optimizing a storage system to write objects in an object store is that both can be done by writing content in moderate-sized chunks (on the order of a megabyte to a few megabytes) and leaving that content in place, unmodified, until some garbage collection process frees up their content (through recognizing it is no longer needed or from moving some remaining content elsewhere), at which point it can be deleted, in the case of objects, or erased for future reuse, in the case of flash storage. In the case of flash, these organize into erase blocks that must be “erased” before any reuse or overwrite. In the case of objects, writing whole moderate-sized objects at once and never modifying them is much more efficient and predictable than writing smaller objects, writing them incrementally, or overwriting them in place.

This creates an interesting point of architectural similarity that can be leveraged by certain flash-optimized storage systems to adapt more easily to object storage. To handle this, a virtual drive implemented by a virtual storage device could implement a model whereby the storage system “writes” medium-sized chunks (on the order of, say, 1 to 32 megabytes) which are received by a virtual device server and written to its local instance storage and into a unique object created for that write. The object, or some combination of the object and object store bucket, could be named based on a storage system's dataset identifier, the virtual drive, and a logical offset, or based on the storage system's dataset identifier and some logical data segment identifier that is separate from the virtual drive and a backward compatible logical offset.

An advantage of the first model for naming an object is that it can closely mimic the layout characteristics of flash storage devices presented to a storage system in a physical storage system. In this model, reading content from the object store backing a virtual device involves fetching as a data segment the object for the storage system's dataset, for a particular virtual device, and at the particular logical offset the storage system associated with that segment. The equivalent of “erasing” a segment that has been garbage collected is to delete the object named by the storage system dataset, the virtual drive, and the segment offset. This leaves a problem if the storage system is going to reuse segments, since writing a new object with the same name as an old object runs into an issue with the “eventual consistency” model in some object stores: specifically, when writing a new object with a never-before-used name, when the object's PUT completes, the object is guaranteed to be durable, but any other case (such as overwriting or reusing an object name) provides only a guarantee that once the change is propagated to enough of the cloud platform's infrastructure it will be durable, but there are no guarantees on when that will be. Reusing segments is not a necessary feature if the storage system can be modified to always generate new segment offsets, but that might require changing how the storage system understands its physically available capacity. Another issue is that deletions also have an eventual consistency issue, so a later recovery of the dataset might encounter segments that the virtual storage system implementation had already “confirmed” were deleted which could cause confusion or corruption if the storage system isn't prepared for that.

One way to handle this issue with that first model for naming an object is to map each fresh write of a segment at the same offset for a storage system dataset and virtual drive to a new name, such as by adding a unique “overwrite” or epoch identifier to the object name. An epoch identifier would change to a new value between the time one or more segments are logically “erased” and the time any of those segments are logically rewritten. An overwrite identifier would be associated with each logical virtual drive segment offset and would advance for that segment somewhere between the time an erase is requested and the time it is rewritten. Then, to read an object for a segment, the virtual device server would have to know the storage system dataset identifier, the virtual drive identifier, the logical segment offset, and the epoch identifier or the overwrite identifier. The epoch or overwrite identifier for a logical segment could be stored in a high-scale key-value store database, such as DynamoDB, as long as it has similar durability to the object store.

If a virtual device server fails and a virtual storage drive's content has to be reconstituted on a new virtual device server by reading its objects from the backing object store, the new virtual device server can connect to the associated segment overwrite table and use its content to construct how the objects for each segment offset are named. It can then proceed to pull those objects in to be stored in the new virtual device server's local instance storage, either on demand (if the local instance storage is used as a cache) or as a high-bandwidth retrieval operation if the local instance storage is intended to be a complete copy of the virtual drive. The overwrite identifier table can be used to determine which objects actual exist (and thus which logical offsets have stored data), which are most current, and what their actual names are which can be constructed from some combination of the virtual storage system dataset identifier, the virtual drive, the logical offset, and the overwrite or epoch identifier.

If a virtual storage server is expected to store the entire content of a virtual drive, and if a new virtual storage device server for a virtual drive is expected to retrieve all that content before it can serve the virtual drive, then a simple advancing epoch identifier associated with a virtual drive can eliminate the need for the key-value database. Instead, the new virtual storage device server can query the object store to retrieve all object names for a dataset and virtual device combination and can sort by logical offset and epoch identifier, ignoring content with the same logical offset. The virtual storage device server would then retrieve objects for each listed logical offset based on the logical offset's most recent epoch identifier (which can be readily determined from the sort). When ready to serve the virtual drive, the virtual storage device server will continue further advancing the epoch identifier. This could require that when the epoch identifier is advanced that it is written into some database with durability roughly matching the object store, so that when a virtual storage device server is rebooted, or a virtual drive is reconstituted on an alternate virtual store device server, the epoch identifier can reliably advance to a new value that has not previously been used. A higher-performance alternative persists epoch identifier into a database after some number of advances and then advances the epoch identifier for the virtual drive by at least that same some number of advances when the virtual storage device server is rebooted or the virtual drive is reconstituted elsewhere. This might be done, say, every 100 epoch advances, so that on a reboot or reconstitute, the current persisted value is retrieved and advanced by at least that same 100.

An alternative to naming segments stored as objects by virtual drive offset is to modify the storage system implementation to keep the concept of stored moderate-sized segments that are garbage collected, but to change how they are indexed and stored. An important point is that object stores are very durable and very resistant to corruption. As a result, there is little reason to store erasure codes between objects. Instance stores, on the other hand, have a durability issue due to their local nature. If a virtual storage device server or one of its local instance store volumes were to fail, the content can be reconstructed from the backing object store, although this would involve a latency hit. As a result, it may not make sense to continue using an erasure coding scheme (e.g., some variant of RAID-6) across virtual drives used by a storage system, but there are few reasons beyond implementation compatibility to do the same for data stored in the object store.

As a result, it makes sense to store data into local instance stores across virtual drives with erasure coded stripes of some kind, and to store data in object stores with no erasure coding at all (at least none under the direction of the virtual storage system or the virtual storage device servers—the object store implementation may well make extensive use of erasure coding internally, but that is opaque to the virtual storage system or the virtual storage device servers that we are describing here).

One simple way to accomplish virtual drives storing data but not parity into object stores would be to keep the format the same, except that virtual drive content that was only erasure code check codes (e.g., P and Q parity) wouldn't be stored into the object store. If such data had to be reconstructed from objects in order to recreate the P and/or Q blocks for a segment on virtual drives, it could be reconstructed either from the local instance stores on other virtual drives that contain matching data blocks, or the data blocks would be retrieved from the object store and the P and/or Q blocks would be calculated from them. If an entire virtual drive has to be reconstructed, such as to a replaced virtual storage device server, the virtual storage system or the virtual storage device server (whichever was managing the process or whichever one was handling the network traffic and requests) would have a choice of retrieving data blocks directly from the object store (which involves retrieving and transferring over the network only the number of data blocks being recovered) or recalculating the content from the data and P or Q blocks from the local instance storage on other virtual storage devices associated with each stripe (which involves retrieving and transferring over the network N times as much data as is being recovered, where N is the number of data shards in the stripe). In an 8+2 RAID-6-style stripe model, for example, if the parity shards are evenly scattered between virtual drives then 80% of the content of the virtual drive could be rebuilt from the object store as retrievals and transfers of that number of blocks, whereas 20% of the content (the P and Q shards for the virtual drive) would be reconstructed by transferring eight times as much data as the blocks being rebuilt either from local instance storage on other virtual storage device servers or from the object store or from some combination.

This implementation might require that the virtual storage system inform the virtual device server which blocks are data and which require reconstruction from other shards. It might also require that data be indicated as check code data when it is being written (so that the virtual device server knows it doesn't need to be mirrored to the object store), or it might require that the virtual storage system implementation inform the virtual storage system of the striping and sharding model for any data stripe the virtual storage system is writing. Alternately, the striping scheme might be predictable or pre-configured for a virtual drive, or for addressable regions of a virtual drive, allowing the virtual storage device server to determine on its own whether a unit of blocks is data, which should be stored in an object store, or check code blocks, which do not need to be stored in an object store.

It should be noted that there is a disadvantage to avoiding the storing of check codes into the object store when it is still used for virtual drives. If a complete virtual storage system dataset is to be recovered into virtual drives from an object store, then if the check code shards are not stored in the object store, then all data retrieved from the object store may need to be further transferred at least once between virtual drives, since the check code shards (e.g., P and Q for a RAID-6-style erasure coded stripe) are calculated by combining the data shards of a stripe together using binary mathematical operators which depends on both operands (e.g., a block of data content and a partial result) residing in memory on the same compute instance, with the result either transferred to (or computed within) the virtual storage device servers with the local instance storage that stores the check code shards for an erasure coded stripe. If, instead, the check code shards are also stored in the object store, then all content (including those check codes) can be retrieved in parallel from the object store into all virtual drives without any further network transfers between virtual storage device servers. Whether one model or the other is preferable may depend on the costs of network traffic between virtual storage device servers, the cost of retrieval from an object store, and the cost of storing otherwise unnecessary check data in the object store. The object store retrieval and storage costs can be reduced significantly by using wider stripes. For example, with 20+2 stripes, the retrieval and capacity overhead is only 10%. Then, full retrievals of an entire virtual storage system dataset might be rare. The total network traffic for rebuilding only one virtual drive, as long as check block shards are evenly scattered, ends up being about the same either way. For example, with a 10+2 stripe, 90% of the content of virtual drive can be retrieved directly from the object store, and 10% requires transferring 10 times that much data from other virtual storage device servers, which adds up to the same total network transfer. If, however, network transfers between virtual storage device server compute instances is significantly cheaper (e.g., less than 10% the cost) versus transfers from object storage, then it might be better to rebuild a single virtual drive entirely from other virtual drives, and the total network transfer savings from storing check blocks may be economically detrimental.

Another way to accomplish this goal (implementing the storage system by using erasure codes for data stored in local instance stores across virtual drives, while avoiding erasure codes for the same data stored in object stores) is to separate the storing of segments across virtual drives from the storing of segments into an object store. For example, a unit of data that the overall virtual storage system might call a protected segment might by erasure coded across a set of virtual drives, for example as one 16 MB segment sharded and interleaved onto 8 virtual drives of data and 2 virtual drives for parity protection, while that segment might be stored as a single 16 MB object in an object store.

This can create a bookkeeping problem, though, as the offset-based indexing for each of the separate shards of the segment stored in virtual drives might not match the scheme that would be used for storing separate objects. Objects would more naturally be stored using objects named by a combination of a virtual storage system dataset identifier and a unique and non-reusable segment identifier. To handle this, references within indexes or other storage system metadata structures might need to include both offset-based addressing and segment identifier-based addressing.

An alternate way of handling the bookkeeping problem is to construct segment identifier to virtual drive mappings as a separate structure. An interesting advantage to this is that the primary durable metadata for the storage system would be based on what is store in the object store, and the virtual drive-oriented index could be reconstructed when rebuilding a virtual storage system dataset from objects in an object store. This would then allow a dataset to be reconstructed into a virtual storage system incorporating a different number of virtual drive servers and virtual drives.

For further explanation, storage system segmenting models and how they map to devices are discussed herein. In particular, there are at least two different models to be discussed. In one model, the storage system defines a segment as a unit of data that is written out as a stripe across multiple storage devices with a size on each device on the order of a megabyte. The storage system's logical segment is thus N×B in size, where N is the number of devices that store data for the logical segment and B is the size of the block stored on each device for the logical segment. If there are an additional R devices that store check codes, then the physical storage for the logical segment is (N+R)×B in size. In the other model, instead of data being striped at the block level, storage system segments are each written as a unit to a particular storage device, and a set of storage system segments are organized together for parity.

Such models open up a range of possibilities. The virtual drive could manage itself as a cache of a range of segments stored in the object store, with the segment identifier to virtual drive mapping held within the virtual drive itself, perhaps using local erasure coding to handle local drive failures (the implementation of local instance stores may already do this) and with fetches from the object store to recover from uncorrected failures or to rebuild the range of segments onto a new virtual drive, such as on a new virtual drive server, if a previous virtual drive or virtual drive server fails.

Alternately a cache, or a complete copy of a virtual storage system dataset, could be managed entirely through the virtual storage system controllers, with virtual drives used to store segments as erasure coded stripes across virtual drives for recovery purposes, but without the virtual storage system controllers necessarily knowing how to transfer their content from object stores. As an optimization in this model, the virtual storage system logic could inform virtual drive servers how to transfer segments to and from the object store while retaining control over when and to which objects and segments within the virtual drives that happens. If segments are erasure coded across virtual drives, then offloading transfers to the virtual drive servers may save on network and CPU bandwidth within the virtual storage system controllers, but doesn't save on that much networking overall, since for an N+R erasure code a virtual driver server that receives a segment will have to transfer N+R−1 shards of that segment to other virtual drive servers.

Alternately, segments could be stored on individual virtual drives (or cached on individual virtual drives), but a set of segments chosen across multiple virtual drives could be linked together to form erasure coded sets that store parity segments on an additional set of virtual drives, so that many types of recoveries can operate within the set of virtual drives (between virtual drive servers, possibly by transferring directly or by transferring through virtual storage system controllers) but transfers of an individual segments to and from a virtual drive generally involves only the virtual drive and the other component involved in the segment transfer. In this model, the virtual storage system logic, when storing a new segment, would store the segment into one virtual drive and that segment would also be stored in an object within the object store. A segment retrieved from the object store might also be stored as a segment within an individual virtual drive, either as a cache or as part of a complete transfer of a dataset into virtual drives. Segments would then be protected by linking a set of those segments across a set of virtual drives and using their content to calculate erasure code parity segments (e.g., P and Q parity segments in a RAID-6 style erasure code scheme). Later garbage collection operations (or perhaps cache discard operations) may have to account for the linked set of segments, such as by discarding or garbage collecting these linked segments (together with their parity segments) rather than garbage collecting or discarding individual segments. In the case of writing new segments, it may make sense for virtual storage system controllers to accumulate the contents of a set of segments in memory and then calculate parity segments to be transferred to virtual drives, or the virtual storage system logic might inform the virtual drives what transfers and calculations to perform in order to compute and store parity segments. In the case of retrievals of segments from an object store, the virtual drives could manage this themselves, or the virtual storage system logic could direct the virtual drives what transfers and calculations to perform, or transfers could flow through virtual storage system controllers so they can calculate and store parity segments.

Virtual storage system logic could divide up segments between virtual drives, or divide the work of transferring segments to and from the object store, in a variety of ways.

Segment identifiers can be hashed to yield a virtual drive. Segment identifiers could include some kind of subset identifier that could be mapped to a virtual drive. Segments could be assigned dynamically to a virtual drive through a table. Within a virtual drive, a segment will likely be stored at an offset within a local storage instance volume. A dynamic mapping of segments means that the durable format of a segment likely can't identify that offset, so there will likely need to be a mapping table somewhere. That table could be managed by virtual drive servers, or it could be managed by virtual storage system controllers. If the virtual storage system controllers keep a table mapping segment identifiers to virtual drives, adding a virtual drive volume offset to that table would be straightforward (though it would add to the memory overhead for that table within virtual storage system controller compute instance memory).

The model of writing segments to individual drives, but linking segments across virtual drives and writing parity segments to one or more additional virtual drives, presents another challenge: that of determining which segments are linked together. This could be done through another table, or segment identifiers could include sequence information that could rotate between virtual drives in a predictable way. Virtual storage system logic must account for this linkage when garbage collecting, when discarding segments for other reasons, and when rebuilding lost data. Of these, only rebuilding lost data has a narrow timeliness element to it, as reading data in response to a client host request is delayed by the time this takes, but even when one or two virtual drives fail, most requests will be directed towards valid data segments stored by non-failed drives, so introducing a table read for that read (particularly compared to the overhead of reading from the other linked segments to rebuild missing data) isn't that big of problem. Virtual storage system logic could also use predictive read heuristics to lessen that latency hit

Storage systems typically make use of some form of fast persistent memory (or other low-latency, high-overwrite-rate storage) for staging updates. This allows quick acknowledgement of updates, and also allows time for data to be organized for writing to longer-term persistent storage. For example, with flash storage it allows time to fill up a set of segments to write into erase blocks and to then protect them with erasure codes across devices, or to add more localized protection as erasure codes or improved checksums within erase blocks or devices to protect against page-level failures. In disk-based storage systems, this can provide time for read-calculate-and-write erasure code updates, while allowing larger work queues to build up for more efficient scheduling of transfers. This fast, persistent memory can also be used to organize transactional updates to ensure consistency of related updates written to backing stores (for example, writing a unit of data and writing an index that references that unit of data, or handling a more complex set of manipulations that may be required to preserve the contents of a snapshot while data for its related volume is being overwritten).

Fast persistent memory can be implemented in a physical storage system as memory and a larger battery, as fast solid state drives, or even as PCI or NVMe or SCSI-connected connected devices with DRAM, a capacitor or other form of rechargeable power such as a rechargeable battery, and local flash, where the DRAM provides low latency and high overwrite rates, and the capacitor or battery provides power to write the DRAM to the flash on power failure. Moving forward, newer forms of non-volatile memory might be used such as 3D Xpoint or MRAM. To ensure that this staging memory can be used for recovering incomplete updates in the face of storage system controller failures, this memory can either be dual ported so that a second storage system controller can read its content if a first storage system controller fails, or the content can be copied by a first storage system controller over some interconnect to a second storage system controller and persisted on that controller as well as on the first before any updates can be acknowledged. To handle failures of the persistent memory itself, there may be two or more such memories and any data is mirrored or erasure coded across them. These fast, persistent memories that are dual ported to multiple compute instances don't quite exist in many cloud platforms, so alternatives are required. Mirroring between virtual storage system controllers can work, though there is still a lack of equivalently fast persistent memory.

With a model in place that allows a flexible relationship between segments stored in an object store and the choice of virtual drive and associated local instance store to store a segment for lower latency and cheaper access, a virtual storage system can readily implement a flexible scaling model. Furthermore, the virtual storage system controllers could divide up a namespace of segment identifiers in such a way that segments are statistically evenly assigned to virtual drives, as part of dividing up work between virtual drives on available virtual drive servers. This assignment could be based, for example, on a hash calculated from the segment identifier, or the segment identifier itself could include some component that indicated some partitioning of the overall dataset that can be assigned to a particular virtual drive. If the number of these partitions, or the means of dividing up the segment identifiers into partitions through a hash resulted in a number of partitions that, was itself sufficiently larger than the current number of virtual drives, then they could be assigned to the currently assigned or available number of virtual drives.

Instead of virtual drive servers handling this independently, virtual storage system logic could either perform the operations to transfer data between objects in the object store and the virtual drives, or could inform the virtual drive servers what transfers to perform. In transfers were performed through the virtual storage system controllers, then the virtual drives could store erasure coded segments entirely independently of the segments stored into objects in the object store. If transfers are performed by the virtual drive servers under instruction from the virtual storage system logic, then an alternate scheme may make sense. Then, if the number of virtual drives for a dataset or a virtual storage system was increased or decreased in the future, such as in response to changes in an application or host client or dataset or sub-dataset SLA or QOS policy or in response to changes in the application, host client, dataset, or sub-dataset load characteristics, or in response to performance interactions.

The storage systems described above may carry out intelligent data backup techniques through which data stored in the storage system may be copied and stored in a distinct location to avoid data loss in the event of equipment failure or some other form of catastrophe. For example, the storage systems described above may be configured to examine each backup to avoid restoring the storage system to an undesirable state. Consider an example in which malware infects the storage system. In such an example, the storage system may include software resources 314 that can scan each backup to identify backups that were captured before the malware infected the storage system and those backups that were captured after the malware infected the storage system. In such an example, the storage system may restore itself from a backup that does not include the malware—or at least not restore the portions of a backup that contained the malware. In such an example, the storage system may include software resources 314 that can scan each backup to identify the presences of malware (or a virus, or some other undesirable), for example, by identifying write operations that were serviced by the storage system and originated from a network subnet that is suspected to have delivered the malware, by identifying write operations that were serviced by the storage system and originated from a user that is suspected to have delivered the malware, by identifying write operations that were serviced by the storage system and examining the content of the write operation against fingerprints of the malware, and in many other ways.

Readers will further appreciate that the backups (often in the form of one or more snapshots) may also be utilized to perform rapid recovery of the storage system. Consider an example in which the storage system is infected with ransomware that locks users out of the storage system. In such an example, software resources 314 within the storage system may be configured to detect the presence of ransomware and may be further configured to restore the storage system to a point-in-time, using the retained backups, prior to the point-in-time at which the ransomware infected the storage system. In such an example, the presence of ransomware may be explicitly detected through the use of software tools utilized by the system, through the use of a key (e.g., a USB drive) that is inserted into the storage system, or in a similar way. Likewise, the presence of ransomware may be inferred in response to system activity meeting a predetermined fingerprint such as, for example, no reads or writes coming into the system for a predetermined period of time.

Readers will appreciate that the various components depicted in FIG. 3B may be grouped into one or more optimized computing packages as converged infrastructures. Such converged infrastructures may include pools of computers, storage and networking resources that can be shared by multiple applications and managed in a collective manner using policy-driven processes. Such converged infrastructures may minimize compatibility issues between various components within the storage system 306 while also reducing various costs associated with the establishment and operation of the storage system 306. Such converged infrastructures may be implemented with a converged infrastructure reference architecture, with standalone appliances, with a software driven hyper-converged approach (e.g., hyper-converged infrastructures), or in other ways.

Readers will appreciate that the storage system 306 depicted in FIG. 3B may be useful for supporting various types of software applications. For example, the storage system 306 may be useful in supporting artificial intelligence (‘AI’) applications, database applications, DevOps projects, electronic design automation tools, event-driven software applications, high performance computing applications, simulation applications, high-speed data capture and analysis applications, machine learning applications, media production applications, media serving applications, picture archiving and communication systems (‘PACS’) applications, software development applications, virtual reality applications, augmented reality applications, and many other types of applications by providing storage resources to such applications.

The storage systems described above may operate to support a wide variety of applications. In view of the fact that the storage systems include compute resources, storage resources, and a wide variety of other resources, the storage systems may be well suited to support applications that are resource intensive such as, for example, AI applications. Such AI applications may enable devices to perceive their environment and take actions that maximize their chance of success at some goal. Examples of such AI applications can include IBM Watson, Microsoft Oxford, Google DeepMind, Baidu Minwa, and others. The storage systems described above may also be well suited to support other types of applications that are resource intensive such as, for example, machine learning applications. Machine learning applications may perform various types of data analysis to automate analytical model building. Using algorithms that iteratively learn from data, machine learning applications can enable computers to learn without being explicitly programmed. One particular area of machine learning is referred to as reinforcement learning, which involves taking suitable actions to maximize reward in a particular situation. Reinforcement learning may be employed to find the best possible behavior or path that a particular software application or machine should take in a specific situation. Reinforcement learning differs from other areas of machine learning (e.g., supervised learning, unsupervised learning) in that correct input/output pairs need not be presented for reinforcement learning and sub-optimal actions need not be explicitly corrected.

In addition to the resources already described, the storage systems described above may also include graphics processing units (‘GPUs’), occasionally referred to as visual processing unit (‘VPUs’). Such GPUs may be embodied as specialized electronic circuits that rapidly manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. Such GPUs may be included within any of the computing devices that are part of the storage systems described above, including as one of many individually scalable components of a storage system, where other examples of individually scalable components of such storage system can include storage components, memory components, compute components (e.g., CPUs, FPGAs, ASICs), networking components, software components, and others. In addition to GPUs, the storage systems described above may also include neural network processors (‘NNPs’) for use in various aspects of neural network processing. Such NNPs may be used in place of (or in addition to) GPUs and may also be independently scalable.

As described above, the storage systems described herein may be configured to support artificial intelligence applications, machine learning applications, big data analytics applications, and many other types of applications. The rapid growth in these sort of applications is being driven by three technologies: deep learning (DL), GPU processors, and Big Data. Deep learning is a computing model that makes use of massively parallel neural networks inspired by the human brain. Instead of experts handcrafting software, a deep learning model writes its own software by learning from lots of examples. A GPU is a modern processor with thousands of cores, well-suited to run algorithms that loosely represent the parallel nature of the human brain.

Advances in deep neural networks have ignited a new wave of algorithms and tools for data scientists to tap into their data with artificial intelligence (AI). With improved algorithms, larger data sets, and various frameworks (including open-source software libraries for machine learning across a range of tasks), data scientists are tackling new use cases like autonomous driving vehicles, natural language processing and understanding, computer vision, machine reasoning, strong AI, and many others. Applications of such techniques may include: machine and vehicular object detection, identification and avoidance; visual recognition, classification and tagging; algorithmic financial trading strategy performance management; simultaneous localization and mapping; predictive maintenance of high-value machinery; prevention against cyber security threats, expertise automation; image recognition and classification; question answering; robotics; text analytics (extraction, classification) and text generation and translation; and many others. Applications of AI techniques has materialized in a wide array of products include, for example, Amazon Echo's speech recognition technology that allows users to talk to their machines, Google Translate™ which allows for machine-based language translation, Spotify's Discover Weekly that provides recommendations on new songs and artists that a user may like based on the user's usage and traffic analysis, Quill's text generation offering that takes structured data and turns it into narrative stories, Chatbots that provide real-time, contextually specific answers to questions in a dialog format, and many others. Furthermore, AI may impact a wide variety of industries and sectors. For example, AI solutions may be used in healthcare to take clinical notes, patient files, research data, and other inputs to generate potential treatment options for doctors to explore. Likewise, AI solutions may be used by retailers to personalize consumer recommendations based on a person's digital footprint of behaviors, profile data, or other data.

Training deep neural networks, however, requires both high quality input data and large amounts of computation. GPUs are massively parallel processors capable of operating on large amounts of data simultaneously. When combined into a multi-GPU cluster, a high throughput pipeline may be required to feed input data from storage to the compute engines. Deep learning is more than just constructing and training models. There also exists an entire data pipeline that must be designed for the scale, iteration, and experimentation necessary for a data science team to succeed.

Data is the heart of modern AI and deep learning algorithms. Before training can begin, one problem that must be addressed revolves around collecting the labeled data that is crucial for training an accurate AI model. A full scale AI deployment may be required to continuously collect, clean, transform, label, and store large amounts of data. Adding additional high quality data points directly translates to more accurate models and better insights. Data samples may undergo a series of processing steps including, but not limited to: 1) ingesting the data from an external source into the training system and storing the data in raw form, 2) cleaning and transforming the data in a format convenient for training, including linking data samples to the appropriate label, 3) exploring parameters and models, quickly testing with a smaller dataset, and iterating to converge on the most promising models to push into the production cluster, 4) executing training phases to select random batches of input data, including both new and older samples, and feeding those into production GPU servers for computation to update model parameters, and 5) evaluating including using a holdback portion of the data not used in training in order to evaluate model accuracy on the holdout data. This lifecycle may apply for any type of parallelized machine learning, not just neural networks or deep learning. For example, standard machine learning frameworks may rely on CPUs instead of GPUs but the data ingest and training workflows may be the same. Readers will appreciate that a single shared storage data hub creates a coordination point throughout the lifecycle without the need for extra data copies among the ingest, preprocessing, and training stages. Rarely is the ingested data used for only one purpose, and shared storage gives the flexibility to train multiple different models or apply traditional analytics to the data.

Readers will appreciate that each stage in the AI data pipeline may have varying requirements from the data hub (e.g., the storage system or collection of storage systems). Scale-out storage systems must deliver uncompromising performance for all manner of access types and patterns—from small, metadata-heavy to large files, from random to sequential access patterns, and from low to high concurrency. The storage systems described above may serve as an ideal AI data hub as the systems may service unstructured workloads. In the first stage, data is ideally ingested and stored on to the same data hub that following stages will use, in order to avoid excess data copying. The next two steps can be done on a standard compute server that optionally includes a GPU, and then in the fourth and last stage, full training production jobs are run on powerful GPU-accelerated servers. Often, there is a production pipeline alongside an experimental pipeline operating on the same dataset. Further, the GPU-accelerated servers can be used independently for different models or joined together to train on one larger model, even spanning multiple systems for distributed training. If the shared storage tier is slow, then data must be copied to local storage for each phase, resulting in wasted time staging data onto different servers. The ideal data hub for the AI training pipeline delivers performance similar to data stored locally on the server node while also having the simplicity and performance to enable all pipeline stages to operate concurrently.

A data scientist works to improve the usefulness of the trained model through a wide variety of approaches: more data, better data, smarter training, and deeper models. In many cases, there will be teams of data scientists sharing the same datasets and working in parallel to produce new and improved training models. Often, there is a team of data scientists working within these phases concurrently on the same shared datasets. Multiple, concurrent workloads of data processing, experimentation, and full-scale training layer the demands of multiple access patterns on the storage tier. In other words, storage cannot just satisfy large file reads, but must contend with a mix of large and small file reads and writes. Finally, with multiple data scientists exploring datasets and models, it may be critical to store data in its native format to provide flexibility for each user to transform, clean, and use the data in a unique way. The storage systems described above may provide a natural shared storage home for the dataset, with data protection redundancy (e.g., by using RAID6) and the performance necessary to be a common access point for multiple developers and multiple experiments. Using the storage systems described above may avoid the need to carefully copy subsets of the data for local work, saving both engineering and GPU-accelerated servers use time. These copies become a constant and growing tax as the raw data set and desired transformations constantly update and change.

Readers will appreciate that a fundamental reason why deep learning has seen a surge in success is the continued improvement of models with larger data set sizes. In contrast, classical machine learning algorithms, like logistic regression, stop improving in accuracy at smaller data set sizes. As such, the separation of compute resources and storage resources may also allow independent scaling of each tier, avoiding many of the complexities inherent in managing both together. As the data set size grows or new data sets are considered, a scale out storage system must be able to expand easily. Similarly, if more concurrent training is required, additional GPUs or other compute resources can be added without concern for their internal storage. Furthermore, the storage systems described above may make building, operating, and growing an AI system easier due to the random read bandwidth provided by the storage systems, the ability to of the storage systems to randomly read small files (50 KB) high rates (meaning that no extra effort is required to aggregate individual data points to make larger, storage-friendly files), the ability of the storage systems to scale capacity and performance as either the dataset grows or the throughput requirements grow, the ability of the storage systems to support files or objects, the ability of the storage systems to tune performance for large or small files (i.e., no need for the user to provision filesystems), the ability of the storage systems to support non-disruptive upgrades of hardware and software even during production model training, and for many other reasons.

Small file performance of the storage tier may be critical as many types of inputs, including text, audio, or images will be natively stored as small files. If the storage tier does not handle small files well, an extra step will be required to pre-process and group samples into larger files. Storage, built on top of spinning disks, that relies on SSD as a caching tier, may fall short of the performance needed. Because training with random input batches results in more accurate models, the entire data set must be accessible with full performance. SSD caches only provide high performance for a small subset of the data and will be ineffective at hiding the latency of spinning drives.

Although the preceding paragraphs discuss deep learning applications, readers will appreciate that the storage systems described herein may also be part of a distributed deep learning (‘DDL’) platform to support the execution of DDL algorithms. Distributed deep learning may can be used to significantly accelerate deep learning with distributed computing on GPUs (or other form of accelerator or computer program instruction executor), such that parallelism can be achieved. In addition, the output of training machine learning and deep learning models, such as a fully trained machine learning model, may be used for a variety of purposes and in conjunction with other tools. For example, trained machine learning models may be used in conjunction with tools like Core ML to integrate a broad variety of machine learning model types into an application. In fact, trained models may be run through Core ML converter tools and inserted into a custom application that can be deployed on compatible devices. The storage systems described above may also be paired with other technologies such as TensorFlow, an open-source software library for dataflow programming across a range of tasks that may be used for machine learning applications such as neural networks, to facilitate the development of such machine learning models, applications, and so on.

Readers will further appreciate that the systems described above may be deployed in a variety of ways to support the democratization of AI, as AI becomes more available for mass consumption. The democratization of AI may include, for example, the ability to offer AI as a Platform-as-a-Service, the growth of Artificial general intelligence offerings, the proliferation of Autonomous level 4 and Autonomous level 5 vehicles, the availability of autonomous mobile robots, the development of conversational AI platforms, and many others. For example, the systems described above may be deployed in cloud environments, edge environments, or other environments that are useful in supporting the democratization of AI. As part of the democratization of AI, a movement may occur from narrow AI that consists of highly scoped machine learning solutions that target a particular task to artificial general intelligence where the use of machine learning is expanded to handle a broad range of use cases that could essentially perform any intelligent task that a human could perform and could learn dynamically, much like a human.

The storage systems described above may also be used in a neuromorphic computing environment. Neuromorphic computing is a form of computing that mimics brain cells. To support neuromorphic computing, an architecture of interconnected “neurons” replace traditional computing models with low-powered signals that go directly between neurons for more efficient computation. Neuromorphic computing may make use of very-large-scale integration (VLSI) systems containing electronic analog circuits to mimic neuro-biological architectures present in the nervous system, as well as analog, digital, mixed-mode analog/digital VLSI, and software systems that implement models of neural systems for perception, motor control, or multisensory integration.

Readers will appreciate that the storage systems described above may be configured to support the storage or use of (among other types of data) blockchains. Such blockchains may be embodied as a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block in a blockchain may contain a hash pointer as a link to a previous block, a timestamp, transaction data, and so on. Blockchains may be designed to be resistant to modification of the data and can serve as an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way. This makes blockchains potentially suitable for the recording of events, medical records, and other records management activities, such as identity management, transaction processing, and others. In addition to supporting the storage and use of blockchain technologies, the storage systems described above may also support the storage and use of derivative items such as, for example, open source blockchains and related tools that are part of the IBM™ Hyperledger project, permissioned blockchains in which a certain number of trusted parties are allowed to access the block chain, blockchain products that enable developers to build their own distributed ledger projects, and others. Readers will appreciate that blockchain technologies may impact a wide variety of industries and sectors. For example, blockchain technologies may be used in real estate transactions as blockchain based contracts whose use can eliminate the need for 3^(rd) parties and enable self-executing actions when conditions are met. Likewise, universal health records can be created by aggregating and placing a person's health history onto a blockchain ledger for any healthcare provider, or permissioned health care providers, to access and update.

Readers will appreciate that the usage of blockchains is not limited to financial transactions, contracts, and the like. In fact, blockchains may be leveraged to enable the decentralized aggregation, ordering, timestamping and archiving of any type of information, including structured data, correspondence, documentation, or other data. Through the usage of blockchains, participants can provably and permanently agree on exactly what data was entered, when and by whom, without relying on a trusted intermediary. For example, SAP's recently launched blockchain platform, which supports MultiChain and Hyperledger Fabric, targets a broad range of supply chain and other non-financial applications.

One way to use a blockchain for recording data is to embed each piece of data directly inside a transaction. Every blockchain transaction may be digitally signed by one or more parties, replicated to a plurality of nodes, ordered and timestamped by the chain's consensus algorithm, and stored permanently in a tamper-proof way. Any data within the transaction will therefore be stored identically but independently by every node, along with a proof of who wrote it and when. The chain's users are able to retrieve this information at any future time. This type of storage may be referred to as on-chain storage. On-chain storage may not be particularly practical, however, when attempting to store a very large dataset. As such, in accordance with embodiments of the present disclosure, blockchains and the storage systems described herein may be leveraged to support on-chain storage of data as well as off-chain storage of data.

Off-chain storage of data can be implemented in a variety of ways and can occur when the data itself is not stored within the blockchain. For example, in one embodiment, a hash function may be utilized and the data itself may be fed into the hash function to generate a hash value. In such an example, the hashes of large pieces of data may be embedded within transactions, instead of the data itself. Each hash may serve as a commitment to its input data, with the data itself being stored outside of the blockchain. Readers will appreciate that any blockchain participant that needs an off-chain piece of data cannot reproduce the data from its hash, but if the data can be retrieved in some other way, then the on-chain hash serves to confirm who created it and when. Just like regular on-chain data, the hash may be embedded inside a digitally signed transaction, which was included in the chain by consensus.

Readers will appreciate that, in some embodiments, alternatives to blockchains may be used to facilitate the decentralized storage of information. For example, one alternative to a blockchain that may be used is a blockweave. While conventional blockchains store every transaction to achieve validation, a blockweave permits secure decentralization without the usage of the entire chain, thereby enabling low cost on-chain storage of data. Such blockweaves may utilize a consensus mechanism that is based on proof of access (PoA) and proof of work (PoW). While typical PoW systems only depend on the previous block in order to generate each successive block, the PoA algorithm may incorporate data from a randomly chosen previous block. Combined with the blockweave data structure, miners do not need to store all blocks (forming a blockchain), but rather can store any previous blocks forming a weave of blocks (a blockweave). This enables increased levels of scalability, speed and low-cost and reduces the cost of data storage in part because miners need not store all blocks, thereby resulting in a substantial reduction in the amount of electricity that is consumed during the mining process because, as the network expands, electricity consumption decreases because a blockweave demands less and less hashing power for consensus as data is added to the system. Furthermore, blockweaves may be deployed on a decentralized storage network in which incentives are created to encourage rapid data sharing. Such decentralized storage networks may also make use of blockshadowing techniques, where nodes only send a minimal block “shadow” to other nodes that allows peers to reconstruct a full block, instead of transmitting the full block itself.

The storage systems described above may, either alone or in combination with other computing devices, be used to support in-memory computing applications. In memory computing involves the storage of information in RAM that is distributed across a cluster of computers. In-memory computing helps business customers, including retailers, banks and utilities, to quickly detect patterns, analyze massive data volumes on the fly, and perform their operations quickly. Readers will appreciate that the storage systems described above, especially those that are configurable with customizable amounts of processing resources, storage resources, and memory resources (e.g., those systems in which blades that contain configurable amounts of each type of resource), may be configured in a way so as to provide an infrastructure that can support in-memory computing. Likewise, the storage systems described above may include component parts (e.g., NVDIMMs, 3D crosspoint storage that provide fast random access memory that is persistent) that can actually provide for an improved in-memory computing environment as compared to in-memory computing environments that rely on RAM distributed across dedicated servers.

In some embodiments, the storage systems described above may be configured to operate as a hybrid in-memory computing environment that includes a universal interface to all storage media (e.g., RAM, flash storage, 3D crosspoint storage). In such embodiments, users may have no knowledge regarding the details of where their data is stored but they can still use the same full, unified API to address data. In such embodiments, the storage system may (in the background) move data to the fastest layer available—including intelligently placing the data in dependence upon various characteristics of the data or in dependence upon some other heuristic. In such an example, the storage systems may even make use of existing products such as Apache Ignite and GridGain to move data between the various storage layers, or the storage systems may make use of custom software to move data between the various storage layers. The storage systems described herein may implement various optimizations to improve the performance of in-memory computing such as, for example, having computations occur as close to the data as possible.

Readers will further appreciate that in some embodiments, the storage systems described above may be paired with other resources to support the applications described above. For example, one infrastructure could include primary compute in the form of servers and workstations which specialize in using General-purpose computing on graphics processing units (‘GPGPU’) to accelerate deep learning applications that are interconnected into a computation engine to train parameters for deep neural networks. Each system may have Ethernet external connectivity, InfiniBand external connectivity, some other form of external connectivity, or some combination thereof. In such an example, the GPUs can be grouped for a single large training or used independently to train multiple models. The infrastructure could also include a storage system such as those described above to provide, for example, a scale-out all-flash file or object store through which data can be accessed via high-performance protocols such as NFS, S3, and so on. The infrastructure can also include, for example, redundant top-of-rack Ethernet switches connected to storage and compute via ports in MLAG port channels for redundancy. The infrastructure could also include additional compute in the form of whitebox servers, optionally with GPUs, for data ingestion, pre-processing, and model debugging. Readers will appreciate that additional infrastructures are also be possible.

Readers will appreciate that the systems described above may be better suited for the applications described above relative to other systems that may include, for example, a distributed direct-attached storage (DDAS) solution deployed in server nodes. Such DDAS solutions may be built for handling large, less sequential accesses but may be less able to handle small, random accesses. Readers will further appreciate that the storage systems described above may be utilized to provide a platform for the applications described above that is preferable to the utilization of cloud-based resources as the storage systems may be included in an on-site or in-house infrastructure that is more secure, more locally and internally managed, more robust in feature sets and performance, or otherwise preferable to the utilization of cloud-based resources as part of a platform to support the applications described above. For example, services built on platforms such as IBM's Watson may require a business enterprise to distribute individual user information, such as financial transaction information or identifiable patient records, to other institutions. As such, cloud-based offerings of AI as a service may be less desirable than internally managed and offered AI as a service that is supported by storage systems such as the storage systems described above, for a wide array of technical reasons as well as for various business reasons.

Readers will appreciate that the storage systems described above, either alone or in coordination with other computing machinery may be configured to support other AI related tools. For example, the storage systems may make use of tools like ONXX or other open neural network exchange formats that make it easier to transfer models written in different AI frameworks. Likewise, the storage systems may be configured to support tools like Amazon's Gluon that allow developers to prototype, build, and train deep learning models. In fact, the storage systems described above may be part of a larger platform, such as IBM™ Cloud Private for Data, that includes integrated data science, data engineering and application building services. Such platforms may seamlessly collect, organize, secure, and analyze data across an enterprise, as well as simplify hybrid data management, unified data governance and integration, data science and business analytics with a single solution.

Readers will further appreciate that the storage systems described above may also be deployed as an edge solution. Such an edge solution may be in place to optimize cloud computing systems by performing data processing at the edge of the network, near the source of the data. Edge computing can push applications, data and computing power (i.e., services) away from centralized points to the logical extremes of a network. Through the use of edge solutions such as the storage systems described above, computational tasks may be performed using the compute resources provided by such storage systems, data may be storage using the storage resources of the storage system, and cloud-based services may be accessed through the use of various resources of the storage system (including networking resources). By performing computational tasks on the edge solution, storing data on the edge solution, and generally making use of the edge solution, the consumption of expensive cloud-based resources may be avoided and, in fact, performance improvements may be experienced relative to a heavier reliance on cloud-based resources.

While many tasks may benefit from the utilization of an edge solution, some particular uses may be especially suited for deployment in such an environment. For example, devices like drones, autonomous cars, robots, and others may require extremely rapid processing so fast, in fact, that sending data up to a cloud environment and back to receive data processing support may simply be too slow. Likewise, machines like locomotives and gas turbines that generate large amounts of information through the use of a wide array of data-generating sensors may benefit from the rapid data processing capabilities of an edge solution. As an additional example, some IoT devices such as connected video cameras may not be well-suited for the utilization of cloud-based resources as it may be impractical (not only from a privacy perspective, security perspective, or a financial perspective) to send the data to the cloud simply because of the pure volume of data that is involved. As such, many tasks that really on data processing, storage, or communications may be better suited by platforms that include edge solutions such as the storage systems described above.

Consider a specific example of inventory management in a warehouse, distribution center, or similar location. A large inventory, warehousing, shipping, order-fulfillment, manufacturing or other operation has a large amount of inventory on inventory shelves, and high resolution digital cameras that produce a firehose of large data. All of this data may be taken into an image processing system, which may reduce the amount of data to a firehose of small data. All of the small data may be stored on-premises in storage. The on-premises storage, at the edge of the facility, may be coupled to the cloud, for external reports, real-time control and cloud storage. Inventory management may be performed with the results of the image processing, so that inventory can be tracked on the shelves and restocked, moved, shipped, modified with new products, or discontinued/obsolescent products deleted, etc. The above scenario is a prime candidate for an embodiment of the configurable processing and storage systems described above. A combination of compute-only blades and offload blades suited for the image processing, perhaps with deep learning on offload-FPGA or offload-custom blade(s) could take in the firehose of large data from all of the digital cameras, and produce the firehose of small data. All of the small data could then be stored by storage nodes, operating with storage units in whichever combination of types of storage blades best handles the data flow. This is an example of storage and function acceleration and integration. Depending on external communication needs with the cloud, and external processing in the cloud, and depending on reliability of network connections and cloud resources, the system could be sized for storage and compute management with bursty workloads and variable conductivity reliability. Also, depending on other inventory management aspects, the system could be configured for scheduling and resource management in a hybrid edge/cloud environment.

The storage systems described above may alone, or in combination with other computing resources, serves as a network edge platform that combines compute resources, storage resources, networking resources, cloud technologies and network virtualization technologies, and so on. As part of the network, the edge may take on characteristics similar to other network facilities, from the customer premise and backhaul aggregation facilities to Points of Presence (PoPs) and regional data centers. Readers will appreciate that network workloads, such as Virtual Network Functions (VNFs) and others, will reside on the network edge platform. Enabled by a combination of containers and virtual machines, the network edge platform may rely on controllers and schedulers that are no longer geographically co-located with the data processing resources. The functions, as microservices, may split into control planes, user and data planes, or even state machines, allowing for independent optimization and scaling techniques to be applied. Such user and data planes may be enabled through increased accelerators, both those residing in server platforms, such as FPGAs and Smart NICs, and through SDN-enabled merchant silicon and programmable ASICs.

The storage systems described above may also be optimized for use in big data analytics. Big data analytics may be generally described as the process of examining large and varied data sets to uncover hidden patterns, unknown correlations, market trends, customer preferences and other useful information that can help organizations make more-informed business decisions. Big data analytics applications enable data scientists, predictive modelers, statisticians and other analytics professionals to analyze growing volumes of structured transaction data, plus other forms of data that are often left untapped by conventional business intelligence (BI) and analytics programs. As part of that process, semi-structured and unstructured data such as, for example, internet clickstream data, web server logs, social media content, text from customer emails and survey responses, mobile-phone call-detail records, IoT sensor data, and other data may be converted to a structured form. Big data analytics is a form of advanced analytics, which involves complex applications with elements such as predictive models, statistical algorithms and what-if analyses powered by high-performance analytics systems.

The storage systems described above may also support (including implementing as a system interface) applications that perform tasks in response to human speech. For example, the storage systems may support the execution intelligent personal assistant applications such as, for example, Amazon's Alexa, Apple Siri, Google Voice, Samsung Bixby, Microsoft Cortana, and others. While the examples described in the previous sentence make use of voice as input, the storage systems described above may also support chatbots, talkbots, chatterbots, or artificial conversational entities or other applications that are configured to conduct a conversation via auditory or textual methods. Likewise, the storage system may actually execute such an application to enable a user such as a system administrator to interact with the storage system via speech. Such applications are generally capable of voice interaction, music playback, making to-do lists, setting alarms, streaming podcasts, playing audiobooks, and providing weather, traffic, and other real time information, such as news, although in embodiments in accordance with the present disclosure, such applications may be utilized as interfaces to various system management operations.

The storage systems described above may also implement AI platforms for delivering on the vision of self-driving storage. Such AI platforms may be configured to deliver global predictive intelligence by collecting and analyzing large amounts of storage system telemetry data points to enable effortless management, analytics and support. In fact, such storage systems may be capable of predicting both capacity and performance, as well as generating intelligent advice on workload deployment, interaction and optimization. Such AI platforms may be configured to scan all incoming storage system telemetry data against a library of issue fingerprints to predict and resolve incidents in real-time, before they impact customer environments, and captures hundreds of variables related to performance that are used to forecast performance load.

The storage systems described above may support the serialized or simultaneous execution artificial intelligence applications, machine learning applications, data analytics applications, data transformations, and other tasks that collectively may form an AI ladder. Such an AI ladder may effectively be formed by combining such elements to form a complete data science pipeline, where exist dependencies between elements of the AI ladder. For example, AI may require that some form of machine learning has taken place, machine learning may require that some form of analytics has taken place, analytics may require that some form of data and information architecting has taken place, and so on. As such, each element may be viewed as a rung in an AI ladder that collectively can form a complete and sophisticated AI solution.

The storage systems described above may also, either alone or in combination with other computing environments, be used to deliver an AI everywhere experience where AI permeates wide and expansive aspects of business and life. For example, AI may play an important role in the delivery of deep learning solutions, deep reinforcement learning solutions, artificial general intelligence solutions, autonomous vehicles, cognitive computing solutions, commercial UAVs or drones, conversational user interfaces, enterprise taxonomies, ontology management solutions, machine learning solutions, smart dust, smart robots, smart workplaces, and many others. The storage systems described above may also, either alone or in combination with other computing environments, be used to deliver a wide range of transparently immersive experiences where technology can introduce transparency between people, businesses, and things. Such transparently immersive experiences may be delivered as augmented reality technologies, connected homes, virtual reality technologies, brain-computer interfaces, human augmentation technologies, nanotube electronics, volumetric displays, 4D printing technologies, or others. The storage systems described above may also, either alone or in combination with other computing environments, be used to support a wide variety of digital platforms. Such digital platforms can include, for example, 5G wireless systems and platforms, digital twin platforms, edge computing platforms, IoT platforms, quantum computing platforms, serverless PaaS, software-defined security, neuromorphic computing platforms, and so on.

Readers will appreciate that some transparently immersive experiences may involve the use of digital twins of various “things” such as people, places, processes, systems, and so on. Such digital twins and other immersive technologies can alter the way that humans interact with technology, as conversational platforms, augmented reality, virtual reality and mixed reality provide a more natural and immersive interaction with the digital world. In fact, digital twins may be linked with the real-world, perhaps even in real-time, to understand the state of a thing or system, respond to changes, and so on. Because digital twins consolidate massive amounts of information on individual assets and groups of assets (even possibly providing control of those assets), digital twins may communicate with each other to digital factory models of multiple linked digital twins.

The storage systems described above may also be part of a multi-cloud environment in which multiple cloud computing and storage services are deployed in a single heterogeneous architecture. In order to facilitate the operation of such a multi-cloud environment, DevOps tools may be deployed to enable orchestration across clouds. Likewise, continuous development and continuous integration tools may be deployed to standardize processes around continuous integration and delivery, new feature rollout and provisioning cloud workloads. By standardizing these processes, a multi-cloud strategy may be implemented that enables the utilization of the best provider for each workload. Furthermore, application monitoring and visibility tools may be deployed to move application workloads around different clouds, identify performance issues, and perform other tasks. In addition, security and compliance tools may be deployed for to ensure compliance with security requirements, government regulations, and so on. Such a multi-cloud environment may also include tools for application delivery and smart workload management to ensure efficient application delivery and help direct workloads across the distributed and heterogeneous infrastructure, as well as tools that ease the deployment and maintenance of packaged and custom applications in the cloud and enable portability amongst clouds. The multi-cloud environment may similarly include tools for data portability.

The storage systems described above may be used as a part of a platform to enable the use of crypto-anchors that may be used to authenticate a product's origins and contents to ensure that it matches a blockchain record associated with the product. Such crypto-anchors may take many forms including, for example, as edible ink, as a mobile sensor, as a microchip, and others. Similarly, as part of a suite of tools to secure data stored on the storage system, the storage systems described above may implement various encryption technologies and schemes, including lattice cryptography. Lattice cryptography can involve constructions of cryptographic primitives that involve lattices, either in the construction itself or in the security proof. Unlike public-key schemes such as the RSA, Diffie-Hellman or Elliptic-Curve cryptosystems, which are easily attacked by a quantum computer, some lattice-based constructions appear to be resistant to attack by both classical and quantum computers.

A quantum computer is a device that performs quantum computing. Quantum computing is computing using quantum-mechanical phenomena, such as superposition and entanglement. Quantum computers differ from traditional computers that are based on transistors, as such traditional computers require that data be encoded into binary digits (bits), each of which is always in one of two definite states (0 or 1). In contrast to traditional computers, quantum computers use quantum bits, which can be in superpositions of states. A quantum computer maintains a sequence of qubits, where a single qubit can represent a one, a zero, or any quantum superposition of those two qubit states. A pair of qubits can be in any quantum superposition of 4 states, and three qubits in any superposition of 8 states. A quantum computer with n qubits can generally be in an arbitrary superposition of up to 2{circumflex over ( )}n different states simultaneously, whereas a traditional computer can only be in one of these states at any one time. A quantum Turing machine is a theoretical model of such a computer.

The storage systems described above may also be paired with FPGA-accelerated servers as part of a larger AI or ML infrastructure. Such FPGA-accelerated servers may reside near (e.g., in the same data center) the storage systems described above or even incorporated into an appliance that includes one or more storage systems, one or more FPGA-accelerated servers, networking infrastructure that supports communications between the one or more storage systems and the one or more FPGA-accelerated servers, as well as other hardware and software components. Alternatively, FPGA-accelerated servers may reside within a cloud computing environment that may be used to perform compute-related tasks for AI and ML jobs. Any of the embodiments described above may be used to collectively serve as a FPGA-based AI or ML platform. Readers will appreciate that, in some embodiments of the FPGA-based AI or ML platform, the FPGAs that are contained within the FPGA-accelerated servers may be reconfigured for different types of ML models (e.g., LSTMs, CNNs, GRUs). The ability to reconfigure the FPGAs that are contained within the FPGA-accelerated servers may enable the acceleration of a ML or AI application based on the most optimal numerical precision and memory model being used. Readers will appreciate that by treating the collection of FPGA-accelerated servers as a pool of FPGAs, any CPU in the data center may utilize the pool of FPGAs as a shared hardware microservice, rather than limiting a server to dedicated accelerators plugged into it.

The FPGA-accelerated servers and the GPU-accelerated servers described above may implement a model of computing where, rather than keeping a small amount of data in a CPU and running a long stream of instructions over it as occurred in more traditional computing models, the machine learning model and parameters are pinned into the high-bandwidth on-chip memory with lots of data streaming though the high-bandwidth on-chip memory. FPGAs may even be more efficient than GPUs for this computing model, as the FPGAs can be programmed with only the instructions needed to run this kind of computing model.

The storage systems described above may be configured to provide parallel storage, for example, through the use of a parallel file system such as BeeGFS. Such parallel files systems may include a distributed metadata architecture. For example, the parallel file system may include a plurality of metadata servers across which metadata is distributed, as well as components that include services for clients and storage servers. Through the use of a parallel file system, file contents may be distributed over a plurality of storage servers using striping and metadata may be distributed over a plurality of metadata servers on a directory level, with each server storing a part of the complete file system tree. Readers will appreciate that in some embodiments, the storage servers and metadata servers may run in userspace on top of an existing local file system. Furthermore, dedicated hardware is not required for client services, the metadata servers, or the hardware servers as metadata servers, storage servers, and even the client services may be run on the same machines.

Readers will appreciate that, in part due to the emergence of many of the technologies discussed above including mobile devices, cloud services, social networks, big data analytics, and so on, an information technology platform may be needed to integrate all of these technologies and drive new business opportunities by quickly delivering revenue-generating products, services, and experiences—rather than merely providing the technology to automate internal business processes. Information technology organizations may need to balance resources and investments needed to keep core legacy systems up and running while also integrating technologies to build an information technology platform that can provide the speed and flexibility in areas such as, for example, exploiting big data, managing unstructured data, and working with cloud applications and services. One possible embodiment of such an information technology platform is a composable infrastructure that includes fluid resource pools, such as many of the systems described above that, can meet the changing needs of applications by allowing for the composition and recomposition of blocks of disaggregated compute, storage, and fabric infrastructure. Such a composable infrastructure can also include a single management interface to eliminate complexity and a unified API to discover, search, inventory, configure, provision, update, and diagnose the composable infrastructure.

The systems described above can support the execution of a wide array of software applications. Such software applications can be deployed in a variety of ways, including container-based deployment models. Containerized applications may be managed using a variety of tools. For example, containerized applications may be managed using Docker Swarm, a clustering and scheduling tool for Docker containers that enables IT administrators and developers to establish and manage a cluster of Docker nodes as a single virtual system. Likewise, containerized applications may be managed through the use of Kubernetes, a container-orchestration system for automating deployment, scaling and management of containerized applications. Kubernetes may execute on top of operating systems such as, for example, Red Hat Enterprise Linux, Ubuntu Server, SUSE Linux Enterprise Servers, and others. In such examples, a master node may assign tasks to worker/minion nodes. Kubernetes can include a set of components (e.g., kubelet, kube-proxy, cAdvisor) that manage individual nodes as a well as a set of components (e.g., etcd, API server, Scheduler, Control Manager) that form a control plane. Various controllers (e.g., Replication Controller, DaemonSet Controller) can drive the state of a Kubernetes cluster by managing a set of pods that includes one or more containers that are deployed on a single node. Containerized applications may be used to facilitate a serverless, cloud native computing deployment and management model for software applications. In support of a serverless, cloud native computing deployment and management model for software applications, containers may be used as part of an event handling mechanisms (e.g., AWS Lambdas) such that various events cause a containerized application to be spun up to operate as an event handler.

The systems described above may be deployed in a variety of ways, including being deployed in ways that support fifth generation (‘5G’) networks. 5G networks may support substantially faster data communications than previous generations of mobile communications networks and, as a consequence may lead to the disaggregation of data and computing resources as modern massive data centers may become less prominent and may be replaced, for example, by more-local, micro data centers that are close to the mobile-network towers. The systems described above may be included in such local, micro data centers and may be part of or paired to multi-access edge computing (‘MEC’) systems. Such MEC systems may enable cloud computing capabilities and an IT service environment at the edge of the cellular network. By running applications and performing related processing tasks closer to the cellular customer, network congestion may be reduced and applications may perform better. MEC technology is designed to be implemented at the cellular base stations or other edge nodes, and enables flexible and rapid deployment of new applications and services for customers. MEC may also allow cellular operators to open their radio access network (‘RAN’) to authorized third-parties, such as application developers and content provider. Furthermore, edge computing and micro data centers may substantially reduce the cost of smartphones that work with the 5G network because customer may not need devices with such intensive processing power and the expensive requisite components.

Readers will appreciate that 5G networks may generate more data than previous network generations, especially in view of the fact that the high network bandwidth offered by 5G networks may cause the 5G networks to handle amounts and types of data (e.g., sensor data from self-driving cars, data generated by AR/VR technologies) that weren't as feasible for previous generation networks. In such examples, the scalability offered by the systems described above may be very valuable as the amount of data increases, adoption of emerging technologies increase, and so on.

For further explanation, FIG. 3E illustrates an exemplary computing device 350 that may be specifically configured to perform one or more of the processes described herein. As shown in FIG. 3E, computing device 350 may include a communication interface 352, a processor 354, a storage device 356, and an input/output (“I/O”) module 358 communicatively connected one to another via a communication infrastructure 360. While an exemplary computing device 350 is shown in FIG. 3E, the components illustrated in FIG. 3E are not intended to be limiting. Additional or alternative components may be used in some embodiments. Components of computing device 350 shown in FIG. 3E will now be described in additional detail.

Communication interface 352 may be configured to communicate with one or more computing devices. Examples of communication interface 352 include, without limitation, a wired network interface (such as a network interface card), a wireless network interface (such as a wireless network interface card), a modem, an audio/video connection, and any other suitable interface.

Processor 354 generally represents any type or form of processing unit capable of processing data and/or interpreting, executing, and/or directing execution of one or more of the instructions, processes, and/or operations described herein. Processor 354 may perform operations by executing computer-executable instructions 362 (e.g., an application, software, code, and/or other executable data instance) stored in storage device 356.

Storage device 356 may include one or more data storage media, devices, or configurations and may employ any type, form, and combination of data storage media and/or device. For example, storage device 356 may include, but is not limited to, any combination of the non-volatile media and/or volatile media described herein. Electronic data, including data described herein, may be temporarily and/or permanently stored in storage device 356. For example, data representative of computer-executable instructions 362 configured to direct processor 354 to perform any of the operations described herein may be stored within storage device 356. In some examples, data may be arranged in one or more databases residing within storage device 356.

I/O module 358 may include one or more I/O modules configured to receive user input and provide user output. I/O module 358 may include any hardware, firmware, software, or combination thereof supportive of input and output capabilities. For example, I/O module 358 may include hardware and/or software for capturing user input, including, but not limited to, a keyboard or keypad, a touchscreen component (e.g., touchscreen display), a receiver (e.g., an RF or infrared receiver), motion sensors, and/or one or more input buttons.

I/O module 358 may include one or more devices for presenting output to a user, including, but not limited to, a graphics engine, a display (e.g., a display screen), one or more output drivers (e.g., display drivers), one or more audio speakers, and one or more audio drivers. In certain embodiments, I/O module 358 is configured to provide graphical data to a display for presentation to a user. The graphical data may be representative of one or more graphical user interfaces and/or any other graphical content as may serve a particular implementation. In some examples, any of the systems, computing devices, and/or other components described herein may be implemented by computing device 350.

For further explanation, FIG. 4 sets forth a flow chart illustrating an example of providing application-specific storage by a storage system (406) in accordance with some embodiments of the present disclosure. Although depicted in less detail, the storage system (406) depicted in FIG. 4 may be similar to the storage systems described above. In fact, the storage system (406) depicted in FIG. 4 may be embodied as one of the storage systems described above, as a combination of a plurality of the storage systems described above, as a modified version of one of the storage systems described above, as a combination of a plurality of modified versions of the storage systems described above, or any combination thereof. As such, the storage system (406) depicted in FIG. 4 includes a plurality of storage subsystems (412 a, 412 b, 412 c, 412 n). Each of the storage subsystems (412 a, 412 b, 412 c, 412 n) depicted in FIG. 4 may be embodied, for example, as one or more storage devices, as one or more of the storage systems described above, as modified versions of the storage systems described above, and so on.

The example method depicted in FIG. 4 also includes an application (404) that is executing on a host (402). The application (404) may be embodied, for example, as one or more modules of computer program instructions that are executing, directly or indirectly, on computer hardware such as a CPU. In the example method depicted in FIG. 4, the application (404) may be configured to utilized storage within the storage system (406), for example, by issuing a request to read data from the storage system (406), by issuing a request to write data to the storage system (406), and so on. In the example method depicted in FIG. 4, the application (404) is executing on a host (402). The host (402) may be embodied, for example, as a server that is coupled to the storage system (406) via a data communications network such as a SAN. In alternative embodiments, the application (404) may be executing elsewhere. For example, the application (402) may be executing on computer hardware that is included within the storage system (406) itself, the application (402) may be executing in a cloud computing environment, and so on.

The example method depicted in FIG. 4 can include identifying (408), for the application (404), one or more characteristics associated with the application (404). The one or more characteristics associated with the application (404) may be used to identify how the storage system (406) can best provide storage resources to the application (404). The one or more characteristics associated with the application (404) may include information such as, for example, the type of storage (e.g., block, file, object) that the application (404) will access, the amount of read bandwidth that needs to be provided to the application (404), the amount of write bandwidth that needs to be provided to the application (404), information describing service level agreements that the application (404) must adhere to, information describing quality-of-service (‘QoS’) requirements associated with the application, and many more. In such an example, because the storage system (406) can include a large pool of disparate resources, the one or more characteristics associated with the application (404) can be used to determine which particular storage subsystems (412 a, 412 b, 412 c, 412 n) should be used to provide storage to the application (404).

Consider an example in which a first storage subsystem (412 a) within the storage system (406) is embodied as a storage array that provides block storage to users of the first storage subsystem (412 a) and a second storage subsystem (412 b) within the storage system (406) is embodied as a storage array that provides object storage to users of the second storage subsystem (412 b). In such an example, if the one or more characteristics associated with the application (404) indicates that the application (404) uses block storage, the storage system (406) may make one or more volumes on the first storage subsystem (412 a) available to the application (404). Alternatively, if the one or more characteristics associated with the application (404) indicates that the application (404) uses object storage, the storage system (406) may make one or more object storage pools on the second storage subsystem (412 b) available to the application (404).

Consider an additional example in which a first storage subsystem (412 a) within the storage system (406) is embodied as a high performance storage array that can provide relatively low read latencies, relatively low write latencies, and a relatively large number of IOPS and a second storage subsystem (412 b) within the storage system (406) is embodied as a lower performance storage array that provides relatively high read latencies, relatively high write latencies, and a relatively small number of IOPS. In such an example, if the one or more characteristics associated with the application (404) indicates that the application (404) needs to service a relatively large number of IOPS in a way that is latency sensitive, the storage system (406) may be configured to place data that is accessed by the application (404) on the first storage array. Alternatively, if the one or more characteristics associated with the application (404) indicates that the application (404) only needs to service a relatively small number of IOPS in a way that is not particularly latency sensitive, the storage system (406) may be configured to place data that is accessed by the application (404) on the second storage array and reserve the higher performance storage resources for applications that demand a higher level of performance from the underlying storage.

In the example method depicted in FIG. 4, the one or more characteristics associated with the application (404) may be identified (408) in a variety of ways. In one embodiment, for example, the one or more characteristics associated with the application (404) may be provided to the storage system (406) via a user interface. In such an example, a system administrator or other authorized user may have access to an interface that allows them to specify things like the amount of read bandwidth needed to support the application (404), the number of IOPS that need to be serviced by the application (404), and so on. In this type of embodiment, one or more characteristics associated with the application (404) may be explicitly provided by a user.

In an alternative embodiment, the one or more characteristics associated with the application (404) may be provided to the storage system (406) in a less explicit way. For example, a system administrator or other authorized user may have access to an interface that includes tunable elements (e.g., knobs) that allows them to specify things like a relative amount of performance that is needed by the application, a relative amount of data protection that is required by the application, a relative amount of data security that is required by the application, data compliance requirements for data that is associated with the application, and so on. In such an example, each knob may be presented via a graphical user interface and the user may set each knob to a value between 1-10, where each combination of settings maps to the underlying storage resources that can provide the application with the best match to the combination of settings. Similarly, users may be presented with various classes of storage to select from, where examples of such storage classes can include ‘low performance, low security’ storage, ‘high performance, low security’ storage, ‘low performance, high security’ storage, ‘high performance, high security’ storage, and so on, including classes that have fewer, additional, or other descriptors. In this type of embodiment, one or more characteristics associated with the application (404) may be inferred by the storage system (406) based on input provided by a user.

In an alternative embodiment, the one or more characteristics associated with the application (404) may be provided to the storage system (406) not by user input via a user interface, but rather through the use of APIs and similar tools. For example, an application developer may have access to an API that allows the software developer to specify things like the type of application that the developer has developed, QoS aspects requested by the developer, security related aspects requested by the developer, performance related aspects requested by the developer, and so on. In this type of embodiment, one or more characteristics associated with the application (404) may be gathered by the storage system (406) by providing developers and system administrators with tools that enable the developers and system administrators to provide such information to the storage system (406).

In another alternative embodiment, the one or more characteristics associated with the application (404) may be provided to the storage system (406) via information that describes the application (404). The information that describes the application (404) may be included in metadata that describes the application, the information that describes the application (404) may be provided from a user such as the application developer, the information that describes the application (404) may be extracted from a service level agreement or similar description of the QoS required by the application (404), and in other ways. In this type of embodiment, the one or more characteristics associated with the application (404) may be extracted from or extrapolated from the information that describes the application (404).

Consider an example in which a first storage subsystem (412 a) within the storage system (406) is embodied as a converged infrastructure in which multiple components (e.g., servers, data storage devices, networking equipment, software components, and so on) are grouped into a single, optimized computing package whereas a second storage subsystem (412 b) within the storage system (406) is embodied as a hyper-converged infrastructure with software-defined components that virtualizes all of the elements of conventional hardware-defined systems. In such an example, some types of applications may perform better when using a hyper-converged infrastructure whereas other types of applications may perform better when utilizing a converged infrastructure. In such an example, the information that describes the application (404) may be used to identify a general categorization for the application (e.g., the application is a virtualized desktop application, the application is a database application) and the storage system (406) can use this information to support the application on the storage subsystem that provides better support for that type of application.

In an alternative embodiment, the one or more characteristics associated with the application (404) may be provided to the storage system (406) via monitoring the execution of the application (404). Monitoring the execution of the application (404) may be carried out, for example, by monitoring the application (404) to generate application level statistics for the application (404) such as, for example, the amount of write bandwidth generated by the application, the amount of read bandwidth generated by the application, the number of IOPS generated by the application, and so on. Likewise, the I/O patterns of the application (404) may be monitored and compared to fingerprints for known types of applications. For example, a database application may tend to generate I/O in a first pattern (e.g., random reads) whereas a log analysis application may tend to generate I/O in a second pattern (e.g., sequential reads). In such an example, when the I/O patterns of a particular application (404) match up reasonably well with fingerprints for known types of applications, the storage system (406) may assume that the one or more characteristics associated with the application (404) are similar to similar applications. In this type of embodiment, the one or more characteristics associated with the application (404) may be generated by observing the actual execution of the application (404).

Readers will appreciate that identifying (408) one or more characteristics associated with the application (404) may be carried out in additional ways and that some characteristics associated with the application (404) may be identified (408) in one way while other characteristics associated with the application (404) may be identified (408) in another way. For example, some characteristics associated with the application (404) may be identified (408) by observing the actual execution of the application (404) whereas other characteristics associated with the application (404) may be explicitly provided by a user.

The example method depicted in FIG. 4 also includes selecting (410), in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406), one or more storage resources within the storage system (406) to support the execution of the application (404). Selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) may be carried out, for example, by comparing the one or more characteristics associated with the application (404) and the characteristics of storage resources within the storage system (406) to identify a best fit. In such an example, multiple aspects of the one or more characteristics associated with the application (404) and the characteristics of storage resources within the storage system (406) may be taken into consideration, in a weighted or unweighted fashion, to identify the set of storage resources that would provide the best fit for the application (404) given the characteristics associated with the application (404).

For further explanation, FIG. 5 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system (406) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 5 is similar to the example method depicted in FIG. 4, as the example method depicted in FIG. 5 also includes identifying (408) one or more characteristics associated with an application (404) and selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406).

In the example method depicted in FIG. 5, the storage system (406) supports the execution of a plurality of applications (404, 504). The storage system (406) may support the execution of a plurality of applications (404, 504), for example, by serving as data storage resources that may be used by the applications (404, 504), by executing one or more modules of computer program instructions that form the applications (404, 504), or in some other way. In the example depicted in FIG. 5, a second application (504) is illustrated as being executed on a second host (502), which may be coupled to the storage system (406) via one or more data communications networks.

In the example method depicted in FIG. 5, for each application (404, 504), the storage resources within the storage system (406) that support the execution of the application (404, 504) are located in distinct application isolation domains (506, 508). Each application isolation domain (506, 508) depicted in FIG. 5 may be embodied as one or more mechanisms used to isolate executed software applications from one another so that they do not affect each other. In the example method depicted in FIG. 5, each application isolation domain (506, 508) may be used to segment portions of the storage system (506, 508), such that different policies may be applied to the segmented portions of the storage system (506, 508). For example, a first application isolation domain (506) may be used to support the execution of a first application (404) and may be associated with a first data protection policy, a first data security policy, a first set of performance policies, and so on. Likewise, a second application isolation domain (508) may be used to support the execution of a second application (504) and may be associated with a second data protection policy, a second data security policy, a second set of performance policies, and so on.

Readers will appreciate that, through the use of application isolation domains (506, 508), data for a particular application may be managed in a way that is most appropriate for that particular application. For example, if a first application (404) has relatively tight recovery point objectives, the application isolation domain (506) that is used to support the application (404) may replicate (i.e., backup) data relatively frequently. Alternatively, if a second application (504) has relatively relaxed recovery point objectives, the application isolation domain (508) that is used to support the application (504) may replicate (i.e., backup) data relatively infrequently. Readers will appreciate that other aspects of data management may also be carried out differently across different application isolation domains (506, 508).

Readers will further appreciate that, through the use of application isolation domains (506, 508), the extent to which a particular application consumes system resources may also be managed. Consider an example in which multiple application isolation domains exist within a single storage subsystem (e.g., a single storage array) within the storage system (406). In such an example, the extent to which one application consumes resources can impact the extent to which another application has access to system resources. For example, if a first application (404) begins generating very large amount of I/O operations, a second application (504) may experience a delay in having its I/O operations serviced as each application may route its I/O operations through the same set of storage controllers within the storage subsystem. In order to prevent such a situation from occurring, the storage system (406) may takes steps such as throttling the application isolation domain (506) that supports the execution of the first application (404) such that only a predetermined amount of IOPS, read bandwidth, write bandwidth, or some other quantifiable measure of total system resources for the storage subsystem that supports each application isolation domain (506, 508) is made available to the application isolation domain (506) that is being throttled.

For further explanation, FIG. 6 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system (406) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 6 is similar to the example methods depicted in FIG. 4 and FIG. 5, as the example method depicted in FIG. 6 also includes identifying (408) one or more characteristics associated with an application (404) and selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406).

As described in greater detail above, storage resources within the storage system (406) are selected (410) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406). Readers will appreciate that, over time, the characteristics associated with the application (404) may change. For example, if the application is embodied as a web portal for a particular retailer, the retailer may expand its customer base through effective advertising, the delivery of superior products, or for a variety of reasons. In such an example, the characteristics associated with the application (404) may also change due to an increase in traffic to the retailer's website. Readers will also appreciate that, over time, the characteristics of storage resources within the storage system (406) may also change. For example, older components (e.g., storage devices) in a particular storage subsystem may be replaced with newer components, components within a particular storage subsystem may age and fail, additional components may be added within a particular storage subsystem, additional storage subsystems may be added to the storage system (406), and so on. Because the one or more characteristics associated with the application (404) and the characteristics of storage resources within the storage system (406) are not static, as either characteristic set changes, the storage resources within the storage system (406) that would be selected (410) to support the execution of the application (404) may change as well. As such, embodiments of the present disclosure can include periodically (or even in response to some event) selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406).

In the example method depicted in FIG. 6, when one iteration of selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406) yields a different result that a previous iteration of selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406), various actions may be taken by the storage system (406).

One example of an action that may be taken by the storage system (406) in response to a different outcome being generated when selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) is to generate (602) a recommendation to cease supporting the execution of the application (404) on first storage resources within the storage system (406) and begin supporting the execution of the application (404) on second storage resources within the storage system (406). Such a recommendation may be presented, for example, to a user such as a system administrator or application developer such that the user can choose whether to accept the recommendation. In such an example, if the user decides to accept the recommendation, a process may be initiated to move data, modify data communications connections, and so on, to enable the application (404) to use the updated set of storage resources within the storage system (406). For example, if the storage system (406) initially selected (410) a first storage subsystem (412 a) to support the execution of the first application (404), but the storage system (406) subsequently selected (410) a second storage subsystem (412 b) to support the execution of the first application (404), data associated with the first application (404) may be migrated from the first storage subsystem (412 a) to the second storage subsystem (412 b), connection information may be updated such that I/Os issued by the first storage subsystem (412 a), and so on.

An additional example of an action that may be taken by the storage system (406) in response to a different outcome being generated when selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) is for the storage system (406) to cease (604) supporting the execution of the application (404) on first storage resources within the storage system (406) and begin supporting (606) the execution of the application (404) on second storage resources within the storage system (406). In such an example, a process may be initiated to move data, modify data communications connections, and so on, to enable the application (404) to use the updated set of storage resources within the storage system (406). Readers will appreciate that the two examples described above represent differing levels of automation that may be implemented and that some embodiments are also possible.

For further explanation, FIG. 7 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system (406) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 7 is similar to the example methods depicted in FIGS. 4-6, as the example method depicted in FIG. 7 also includes identifying (408) one or more characteristics associated with an application (404) and selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406).

The example method depicted in FIG. 7 also includes predicting (702) a change to the application (404). Predicting (702) a change to the application may be carried out, for example, by detecting that the application itself has changed and even by projecting a change to the application over time. In such an example, projecting a change to the application (404) over time may be carried out by performing a time-series analysis of various performance metrics associated with the application (404) to identify trends associated with the application (404). In addition, projecting a change to the application (404) over time may also be carried out based on telemetry data collected for similar applications as the telemetry data may be useful for identifying trends associated with the application (404). As such, an examination of the various performance metrics associated with the application (404) and the telemetry data can be used to generate trending information for the applications (404) including, for example, information describing the rate at which the number of IOPS being generated by the application (404) has been changing, the rate at which overwrite rates for I/O operations that are being generated by the application (404) are changing, the rate at which the amount of read bandwidth that is being consumed by I/O operations generated by the application (404) is changing, and many others. In such a way, predicted characteristics (416) of the application (404) may be generated by extrapolating identified trends out over a period of time in the future.

Consider an example in which telemetry data gathered from a plurality of storage systems indicates that, on average, the amount of CPU resources required to support a virtual desktop infrastructure workload doubles every three years. In such an example, if a particular application (404) is a virtual desktop infrastructure workload, predicting (702) a change to the application (404) may be carried out, at least in part, by determining the amount of CPU resources currently required to support the application (404) and assuming that the amount of CPU resources that will be required to support the application (404) in the future will double every three years. In such a way, the load demands created by each application (404) may be projected to some point in the future.

The example method depicted in FIG. 7 also includes identifying (704), in dependence upon the predicted change to the application (404), one or more updated characteristics associated with the application (404). Identifying (704) one or more updated characteristics associated with the application (404) may be carried out, for example, by utilizing trending information associated with the application (404) itself, trending information associated with the application (404) itself and trending information based on telemetry data associated with similar applications, or some combination thereof, to project how the application (404) will operate in the future.

Readers will appreciate that embodiments described herein may also leverage machine learning techniques to not only predicting (702) a change to the application (404) but also to identify (704) one or more updated characteristics associated with the application (404). In such an example, various metrics associated with the application (404) and even similar applications may be fed into a machine learning model to detect the occurrence of changes to the application (404), changes to the application's (404) usage of underlying storage resources, and so on, to gain a better understanding of characteristics that the workload may take on in the future.

The example method depicted in FIG. 7 also includes selecting (706), in dependence upon the one or more updated characteristics associated with the application (404) and characteristics of storage resources within the storage system (406), one or more updated storage resources within the storage system to support the execution of the application (404). Selecting (706) one or more storage resources within the storage system (406) to support the execution of the application (404) may be carried out, for example, by comparing the one or more updated characteristics associated with the application (404) and the characteristics of storage resources within the storage system (406) to identify a best fit. In such an example, multiple aspects of the one or more updated characteristics associated with the application (404) and the characteristics of storage resources within the storage system (406) may be taken into consideration, in a weighted or unweighted fashion, to identify the set of storage resources that would provide the best fit for the application (404) given the updated characteristics associated with the application (404).

For further explanation, FIG. 8 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system (406) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 8 is similar to the example methods depicted in FIGS. 4-7, as the example method depicted in FIG. 8 also includes identifying (408) one or more characteristics associated with an application (404) and selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406).

The example method depicted in FIG. 8 also includes predicting (802) a change to one or more resources within the storage system (406). Readers will appreciate that one or more storage resources may exhibit different behavior, for example, as they age, as components are replaced or upgraded (including software components), as the workloads service by a set of resources change, and for many other reasons. In such an example, the expected changes to the storage resources may be utilized to generate updated characteristics of storage resources within the storage system (406).

The example method depicted in FIG. 8 also includes selecting (804), in dependence upon the one or more characteristics associated with the application (404) and updated characteristics of storage resources within the storage system (406), an updated set of storage resources within the storage system (406) to support the execution of the application (404). Selecting (804) one or more storage resources within the storage system (406) to support the execution of the application (404) may be carried out, for example, by comparing the one or more characteristics associated with the application (404) and the updated characteristics of storage resources within the storage system (406) to identify a best fit. In such an example, multiple aspects of the one or more characteristics associated with the application (404) and the updated characteristics of storage resources within the storage system (406) may be taken into consideration, in a weighted or unweighted fashion, to identify the set of storage resources that would provide the best fit for the application (404) given the updated characteristics of storage resources within the storage system (406).

For further explanation, FIG. 9 sets forth a flow chart illustrating an additional example method of providing application-specific storage by a storage system (406) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 9 is similar to the example methods depicted in FIGS. 4-8, as the example method depicted in FIG. 9 also includes identifying (408) one or more characteristics associated with an application (404) and selecting (410) one or more storage resources within the storage system (406) to support the execution of the application (404) in dependence upon the one or more characteristics associated with the application (404) and characteristics of storage resources within the storage system (406).

The example method depicted in FIG. 9 also includes detecting (902) that one or more storage resources within the storage system (406) will become constrained. Detecting (902) that one or more storage resources within the storage system (406) will become constrained may be carried out, for example, by detecting that the utilization of a particular resource either has or is projected to reach a predetermined utilization level (e.g., 90% of full utilization). Consider the example described above in which multiple application isolation domains exist within a single storage subsystem (e.g., a single storage array) within the storage system (406). In such an example, the extent to which one application consumes resources can impact the extent to which another application has access to system resources. For example, if a first application (404) begins generating very large amount of I/O operations, a second application (504) may experience a delay in having its I/O operations serviced as each application may route its I/O operations through the same set of storage controllers within the storage subsystem. In such an example, detecting (902) that the storage controllers for the particular storage subsystem will become constrained may be carried out, for example, by detecting that the utilization of the storage controllers for the particular storage subsystem either has or is projected to reach the predetermined utilization level.

The example method depicted in FIG. 9 also includes automatically (904), without user intervention, performing corrective actions. In the example method depicted in FIG. 9, the corrective actions may take a variety of forms. For example, automatically (904) performing corrective actions may include, to the extent possible, reconfiguring the storage resources. Consider an example in which the storage controllers for a particular storage subsystem (412 a) are becoming constrained, where the storage controllers are configured to perform inline deduplication and compression of data as it comes into the storage subsystem (412 a) via requests to write data that are issued by the applications that are supported by the storage subsystem (412 a). In such an example, reconfiguring the storage resources may be carried out by reconfiguring the storage controllers to not perform inline deduplication and compression of data as it comes into the storage subsystem (412 a), but rather rely on the storage devices themselves to perform deduplication operations and compression operations on the data once it has been written to non-volatile storage within the storage system (406) by the storage controllers.

As another example of automatically (904) performing corrective actions, the storage system may effectively relocate workloads within the storage system (406). Consider an example in which multiple applications are being supported by a first storage subsystem (412 a) whose storage controllers are becoming constrained. In such an example, the storage system (406) may be configured to automatically migrate a dataset that is associated with one or more of the applications that are being supported by the first storage subsystem (412 a) to a second storage subsystem (412 b) (as well as updating connection information), such that I/O operations generated by the one or more applications whose associated datasets have been migrated to the second storage subsystem (412 b) begin to flow to the second storage subsystem (412 b).

As another example of automatically (904) performing corrective actions, the storage system (406) may limit the amount of resources that may be consumed by particular applications. Consider an example in which multiple applications are being supported by a first storage subsystem (412 a) whose storage controllers are becoming constrained. In such an example, the storage system (406) may be configured to automatically throttle one or more application isolation domains such that only a predetermined amount of IOPS, read bandwidth, write bandwidth, or some other quantifiable measure of total system resources for the storage subsystem that supports the application isolation domain is made available to the application isolation domain that is being throttled.

For further explanation, FIG. 10 sets forth a flow chart illustrating an example method of providing application-specific storage by a cloud-based storage system (1008 a, 1008 b, 1008 n) in accordance with some embodiments of the present disclosure. Although depicted in less detail, the cloud-based storage systems (1008 a, 1008 b, 1008 n) depicted in FIG. 10 may be similar to the cloud-based storage systems described above, including those described with reference to FIG. 3C and FIG. 3D. In fact, the cloud-based storage systems (1008 a, 1008 b, 1008 n) depicted in FIG. 10 may be embodied as one of the storage systems described above, as a combination of a plurality of the storage systems described above, as a modified version of one of the storage systems described above, as a combination of a plurality of modified versions of the storage systems described above, or any combination thereof that is executing within a cloud computing environment (1006).

The example method depicted in FIG. 10 also includes an application (1004) that is executing on a host (1002). The application (1004) may be embodied, for example, as one or more modules of computer program instructions that are executing, directly or indirectly, on computer hardware such as a CPU. In fact, the application (1004) may be executing in a virtualized environment such as on one or more virtual machines, within one or more containers, or in some other way. In the example method depicted in FIG. 10, the application (1004) may be configured to utilized resources within the cloud-based storage system (1008 a, 1008 b, 1008 n), for example, by issuing a request to read data from the cloud-based storage system (1008 a, 1008 b, 1008 n), by issuing a request to write data to the cloud-based storage system (1008 a, 1008 b, 1008 n), and so on. In the example method depicted in FIG. 10, the application (1004) is executing on a host (1002). The host (1002) may be embodied, for example, as a server that is coupled for data communications with the cloud-based storage system (1008 a, 1008 b, 1008 n) via one or more data communications networks and/or APIs into the cloud computing environment (1006), as a virtualized environment (e.g., a virtual machine, a container) that is coupled for data communications with the cloud-based storage system (1008 a, 1008 b, 1008 n) via one or more data communications networks and/or APIs into the cloud computing environment (1006). In alternative embodiments, the application (1004) may be executing elsewhere. For example, the application (1004) may be executing in the cloud computing environment (1006) itself.

The example method depicted in FIG. 10 includes identifying (1010), for an application (1004) that utilizes resources within the cloud-based storage system (1008 a, 1008 b, 1008 n), one or more characteristics associated with the application (1010). The one or more characteristics associated with the application (1004) may include information such as, for example, the amount of read bandwidth that needs to be provided to the application (1004), the amount of write bandwidth that needs to be provided to the application (1004), information describing service level agreements that the application (1004) must adhere to, information describing quality-of-service (‘QoS’) requirements associated with the application (1004), and many more.

In the example method depicted in FIG. 10, the one or more characteristics associated with the application (1004) may be identified (1010) in a variety of ways. In one embodiment, for example, the one or more characteristics associated with the application (1004) may be provided to the cloud-based storage system (1008 a, 1008 b, 1008 n) (or to some management module that pairs applications with the appropriate cloud-based storage system) via a user interface. In such an example, a system administrator or other authorized user may have access to an interface that allows them to specify things like the amount of read bandwidth needed to support the application (1004), the number of IOPS that need to be serviced by the application (1004), and so on. In this type of embodiment, one or more characteristics associated with the application (1004) may be explicitly provided by a user.

In an alternative embodiment, the one or more characteristics associated with the application (1004) may be provided to the cloud-based storage system (1008 a, 1008 b, 1008 n) (or to some management module that pairs applications with the appropriate cloud-based storage system) in a less explicit way. For example, a system administrator or other authorized user may have access to an interface that includes tunable elements (e.g., knobs) that allows them to specify things like a relative amount of performance that is needed by the application, a relative amount of data protection that is required by the application, a relative amount of data security that is required by the application, data compliance requirements for data that is associated with the application, and so on. In such an example, each knob may be presented via a graphical user interface and the user may set each knob to a value between 1-10, where each combination of settings maps to the underlying storage resources that can provide the application with the best match to the combination of settings. Similarly, users may be presented with various classes of storage to select from, where examples of such storage classes can include ‘low performance, low security’ storage, ‘high performance, low security’ storage, ‘low performance, high security’ storage, ‘high performance, high security’ storage, and so on, including classes that have fewer, additional, or other descriptors. In this type of embodiment, one or more characteristics associated with the application (1004) may be inferred based on input provided by a user.

In an alternative embodiment, the one or more characteristics associated with the application (1004) may be provided to the cloud-based storage system (1008 a, 1008 b, 1008 n) (or to some management module that pairs applications with the appropriate cloud-based storage system) not by user input via a user interface, but rather through the use of APIs and similar tools. For example, an application developer may have access to an API that allows the software developer to specify things like the type of application that the developer has developed, QoS aspects requested by the developer, security related aspects requested by the developer, performance related aspects requested by the developer, and so on. In this type of embodiment, one or more characteristics associated with the application (1004) may be gathered by the cloud-based storage system (1008 a, 1008 b, 1008 n) (or to some management module that pairs applications with the appropriate cloud-based storage system) by providing developers and system administrators with tools that enable the developers and system administrators to provide such information to the cloud-based storage system (1008 a, 1008 b, 1008 n) (or to some management module that pairs applications with the appropriate cloud-based storage system).

In another alternative embodiment, the one or more characteristics associated with the application (1004) may be provided to the cloud-based storage system (1008 a, 1008 b, 1008 n) (or to some management module that pairs applications with the appropriate cloud-based storage system) via information that describes the application (1004). The information that describes the application (1004) may be included in metadata that describes the application, the information that describes the application (1004) may be provided from a user such as the application developer, the information that describes the application (1004) may be extracted from a service level agreement or similar description of the QoS required by the application (1004), and in other ways. In this type of embodiment, the one or more characteristics associated with the application (1004) may be extracted from or extrapolated from the information that describes the application (1004).

In an alternative embodiment, the one or more characteristics associated with the application (1004) may be provided to the cloud-based storage system (1008 a, 1008 b, 1008 n) (or to some management module that pairs applications with the appropriate cloud-based storage system) via monitoring the execution of the application (1004). Monitoring the execution of the application (1004) may be carried out, for example, by monitoring the application (1004) to generate application level statistics for the application (1004) such as, for example, the amount of write bandwidth generated by the application, the amount of read bandwidth generated by the application, the number of IOPS generated by the application, and so on. Likewise, the I/O patterns of the application (1004) may be monitored and compared to fingerprints for known types of applications. For example, a database application may tend to generate I/O in a first pattern (e.g., random reads) whereas a log analysis application may tend to generate I/O in a second pattern (e.g., sequential reads). In such an example, when the I/O patterns of a particular application (1004) match up reasonably well with fingerprints for known types of applications, the cloud-based storage system (1008 a, 1008 b, 1008 n) may assume that the one or more characteristics associated with the application (1004) are similar to similar applications. In this type of embodiment, the one or more characteristics associated with the application (1004) may be generated by observing the actual execution of the application (1004).

Readers will appreciate that identifying (1010) one or more characteristics associated with the application (1004) may be carried out in additional ways and that some characteristics associated with the application (1004) may be identified (1010) in one way while other characteristics associated with the application (1004) may be identified (1010) in another way. For example, some characteristics associated with the application (1004) may be identified (1010) by observing the actual execution of the application (1004) whereas other characteristics associated with the application (1004) may be explicitly provided by a user.

The example method depicted in FIG. 10 also includes selecting (1012), in dependence upon the one or more characteristics associated with the application (1004) and characteristics of resources (1016) within one or more cloud-based storage system (1008 a, 1008 b, 1008 n), one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004). Because the cloud-based storage system (1008 a, 1008 b, 1008 n) can include a large pool of disparate resources, the one or more characteristics associated with the application (1004) and the characteristics of each of the resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) can be used to select (1012) which particular resources within an existing cloud-based storage system (1008 a, 1008 b, 1008 n) should be used to provide storage to the application (1004). Assume, for example, that a first storage system virtual controller compute instance (368 a) is embodied as a relatively powerful EC2 instance that can process a relatively large number of I/O operations in a relatively short period of time, whereas a second storage system virtual controller compute instance (368 b) is embodied as a relatively lightweight EC2 instance that can only process a relatively small number of I/O operations in the same period of time. In such an example, if an application (1004) has relatively high performance demands, the first storage system virtual controller compute instance (368 a) may be selected (1012) to serve as the primary controller (as described above) for the application (1004), whereas if the application (1004) has relatively low performance demands, the second storage system virtual controller compute instance (368 b) may be selected (1012) to serve as the primary controller (as described above) for the application (1004). As such, selecting (1012) one or more resources (1016) within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can include selecting, from the resources within a single cloud-based storage system, a subset of the resources within the single cloud-based storage system to support the execution of the application (1004).

In some embodiments, because a new cloud-based storage system (1008 a, 1008 b, 1008 n) can be quickly created with distinct pools of resources, the one or more characteristics associated with the application (1004) and the characteristics of resources (1016) that could be included in a newly created cloud-based storage system (1008 a, 1008 b, 1008 n) can be used to determine the particular configuration (including an identification of the amount and types of resources) of a cloud-based storage system (1008 a, 1008 b, 1008 n) that should be created and used to provide storage to the application (1004). Assume, for example, that the application (1004) has relatively high performance demands. In such an example, a relatively powerful EC2 instance may be selected for inclusion in a cloud-based storage system (1008 a, 1008 b, 1008 n) that is created for use by the application (1004). If the application (1004) has relatively low performance demands, however, a less powerful and relatively lightweight EC2 instance may be selected for inclusion in a cloud-based storage system (1008 a, 1008 b, 1008 n) that is created for use by the application (1004). As such, selecting (1012) one or more resources (1016) within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can include selecting, from available resources that could be included in a cloud-computing system, a subset of resources that can be provided by the cloud computing environment (1006) for inclusion within a cloud-based storage system (1008 a, 1008 b, 1008 n) that is to be created to support the execution of the application (1004).

In embodiments where multiple cloud-based storage systems (1008 a, 1008 b, 1008 n) are supported by the cloud computing environment (1006), the one or more characteristics associated with the application (1004) and the characteristics the resources (1016) within each of the cloud-based storage systems (1008 a, 1008 b, 1008 n) can be used to select (1012) which particular cloud-based storage system (1008 a, 1008 b, 1008 n) should be used to provide storage to the application (1004). Assume, for example, that a first cloud-based storage system (1008 a) is comprised of resources that allow the first cloud-based storage system (1008 a) to provide for relatively low latency, high bandwidth I/O operations whereas a second cloud-based storage system (1008 b) is comprised of resources that allow the second cloud-based storage system (1008 b) to provide for relatively high latency, low bandwidth I/O operations. In such an example, if the one or more characteristics associated with the application (1004) indicated that the application (1004) had relatively high performance demands, the first cloud-based storage system (1008 a) may be selected to support the execution of the application (1004). If the one or more characteristics associated with the application (1004) indicated that the application (1004) had relatively low performance demands, however, the second cloud-based storage system (1008 b) may be selected to support the execution of the application (1004). As such, selecting (1012) one or more resources (1016) within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can include selecting, from amongst a plurality of cloud-based storage systems (1008 a, 1008 b, 1008 n) that are supported by the cloud computing environment (1006), a particular cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004).

Readers will appreciate that although the preceding paragraphs describe selecting (1012) one or more resources (1016) within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) by: 1) selecting, from the resources within a single cloud-based storage system, a subset of the resources within the single cloud-based storage system to support the execution of the application (1004), or 2) selecting, from available resources that could be included in a cloud-computing system, a subset of resources that can be provided by the cloud computing environment (1006) for inclusion within a cloud-based storage system (1008 a, 1008 b, 1008 n) that is to be created to support the execution of the application (1004), or 3) selecting, from amongst a plurality of cloud-based storage systems (1008 a, 1008 b, 1008 n) that are supported by the cloud computing environment (1006), a particular cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004), other methods of selecting (1012) one or more resources (1016) within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) are possible.

Readers will appreciate that combinations of the various methods described above for selecting (1012) one or more resources (1016) within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) are also within the scope of the present disclosure. For example, selecting (1012) one or more resources (1016) within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can be carried out by: 1) selecting, from amongst a plurality of cloud-based storage systems (1008 a, 1008 b, 1008 n) that are supported by the cloud computing environment (1006), a particular cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004), and 2) subsequently selecting, from the resources within the single cloud-based storage system that was selected in step 1, a subset of the resources within the single cloud-based storage system to support the execution of the application (1004). Readers will further appreciate that although, for ease of explanation, the examples described above relate to embodiments where applications are largely described as being high performance or low performance, and cloud-based storage systems are largely described as being high performance or low performance, many other characteristics of the applications and the cloud-based storage systems may be taken into consideration.

In the example method depicted in FIG. 10, at least a portion of a dataset that is associated with the application (1004) is stored as blocks within block storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n) and also stored as objects within object storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n). The dataset that is associated with the application (1004) is depicted in FIG. 10 as a series of dataset slices (1014 a, 1014 b, 1014 n) that collectively form the dataset that is associated with the application (1004). Such a dataset may be ‘associated’ with the application (1004) as the application writes data to the dataset, reads data from the dataset, and so on. In the example depicted in FIG. 10, each dataset slice (1014 a, 1014 b, 1014 n) is stored as blocks within block storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n). More specifically, each dataset slice (1014 a, 1014 b, 1014 n) is stored as blocks of data that are contained within one or more VDrives (372 a, 372 b, 372 n), which are also referred to as virtual drives and cloud computing instances with local storage herein. In the example depicted in FIG. 10, each dataset slice (1014 a, 1014 b, 1014 n) is also stored as objects within object storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n). More specifically, each dataset slice (1014 a, 1014 b, 1014 n) is stored as one or more objects within one or more S3 buckets (392), which are also referred to as cloud-based object storage herein. Readers will appreciate that although S3 buckets are described in this example, other object storage offerings from a cloud services provider, such as blob storage offered by Microsoft's Azure, could also be used. As described in more detail above, in some embodiments the entire dataset may reside within the block storage layer of the cloud-based storage system (1008 a, 1008 b, 1008 n) while in some embodiments only some portion of the entire dataset may reside within the block storage layer of the cloud-based storage system (1008 a, 1008 b, 1008 n).

For further explanation, FIG. 11 sets forth a flow chart illustrating an example method of providing application-specific storage by a cloud-based storage system (1008 a, 1008 b, 1008 n) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 11 is similar to the example method depicted in FIG. 10, as the example method depicted in FIG. 11 also includes identifying (1010), for an application (1004) that utilizes resources within the cloud-based storage system (1008 a, 1008 b, 1008 n), one or more characteristics associated with the application (1010) and selecting (1012), in dependence upon the one or more characteristics associated with the application (1004) and characteristics of resources (1016) within one or more cloud-based storage system (1008 a, 1008 b, 1008 n), one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004). Although not explicitly depicted in FIG. 11, at least a portion of a dataset associated with the application is stored as blocks within block storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n) and also stored as objects within object storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n).

In the example method depicted in FIG. 11, selecting (1012) one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can include selecting (1102), from amongst a plurality of storage system virtual controller compute instances, a particular storage system virtual controller compute instances to service I/O operations generated by the application (1004). As described above, in embodiments where only a single storage system virtual controller compute instance (368 a) can serve as the active (i.e., primary) controller, the storage system virtual controller compute instance that best matches the needs of the application (1004) as indicated in the characteristics of the application (1004), may be selected (1102). Readers will appreciate that in some embodiments compute instances can be created on demand and don't actually need to be selected from a set of existing compute instances. In fact, it is plausible that the virtual storage system controller logic could be embodied as a Lambda function or similar construct, meaning it is run on demand on one or more compute hosts in response to increase and decrease in demand (subject to pricing constraints which could be related to the amount of money a customer is willing to pay for a particular application). In such an example, virtual storage system controller compute instances may be instantiated according to a combination of the application's current run-time characteristics, its SLA, the customer's budget constraints, and so on.

In the example method depicted in FIG. 11, selecting (1012) one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can include selecting (1104), from available resources that could be included in a cloud-based storage system, a subset of resources that can be provided by the cloud computing environment (1006) for inclusion within the cloud-based storage system that is to be created to support the execution of the application (1004). Selecting (1104) a subset of resources that can be provided by the cloud computing environment (1006) for inclusion within the cloud-based storage system that is to be created to support the execution of the application (1004) may be carried out, for example, through the use of one or more formulas/rules that may be used to dynamically determine the type and amount of various components that should be included within the cloud-based storage system that is to be created to support the execution of the application (1004). If characteristics associated with a particular application (1004) indicate that the application (1004) will issue a certain number of IOPS during peak usage, for example, an EC2 instance that can execute the storage controller application in such a way that the storage controller application can service that number of IOPS should be selected (1104) for inclusion within the cloud-based storage system that is to be created to support the execution of the application (1004). Likewise, a sufficient number and type of EC2 instances that are used as virtual drives should be selected (1104) for inclusion within the cloud-based storage system that is to be created to support the execution of the application (1004) such that the virtual drives can service the number of IOPS that the application (1004) is expected to generate.

In an alternative embodiment, one or more templates may also be utilized to select (1104) a subset of resources that can be provided by the cloud computing environment (1006) for inclusion within the cloud-based storage system that is to be created to support the execution of the application (1004). Such templates may include, for example, an identification of a set of resources that are to be included in a cloud-based storage system that is to be used to support applications of a particular type (e.g., a first template may be used for database applications whereas a second template may be used for email applications), an identification of a set of resources that are to be included in a cloud-based storage system that is to be used to support applications of that match a particular profile based on the characteristics of the application, and so on. Readers will appreciate that once a subset of resources that can be provided by the cloud computing environment (1006) for inclusion within the cloud-based storage system that is to be created to support the execution of the application (1004) have been selected (1104), an instance of such a cloud-based storage system may be created to support the execution of the application (1004) by provisioning such resources from the cloud computing environment and configuring such resources to operate as a cloud-based storage system (e.g., configuring the EC2 instances that host the storage controller application to communicate with the EC2 instances that are to be used as virtual drives, configuring the EC2 instances that are to be used as virtual drives to communicate with S3 buckets, and so on).

In the example method depicted in FIG. 11, selecting (1012) one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can include selecting (1106), from amongst a plurality of cloud-based storage systems (1008 a, 1008 b, 1008 n) that are supported by the cloud computing environment (1006), a particular cloud-based storage system to support the execution of the application (1004). Selecting (1106), from amongst a plurality of cloud-based storage systems (1008 a, 1008 b, 1008 n) that are supported by the cloud computing environment (1006), a particular cloud-based storage system to support the execution of the application (1004) may be carried out, for example, by comparing the characteristics associated with the application (1004) to the characteristics associated with each of the cloud-based storage systems (1008 a, 1008 b, 1008 n) to identify a best fit (i.e., to identify a cloud-based storage system (1008 a, 1008 b, 1008 n) that best provides the resources needed by the application (1004)).

In the example method depicted in FIG. 11, selecting (1012) one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can include selecting, from resources within a single cloud-based storage system (1008 a), a subset of the resources within the single cloud-based storage system (1008 a) to support the execution of the application (1004). Selecting a subset of the resources within the single cloud-based storage system to support the execution of the application (1004) may be carried out, for example, by selecting a particular resource within the cloud-based storage system (1008 a) that is best suited to meet the needs of the application. For example, and as described above, when only a single storage system virtual controller compute instance (368 a) can serve as the active (i.e., primary) controller, the storage system virtual controller compute instance that best matches the needs of the application (1004) as indicated in the characteristics of the application (1004), may be selected. Alternatively, selecting a subset of the resources within the single cloud-based storage system to support the execution of the application (1004) may be carried out by selecting a particular group of resources within the cloud-based storage system (1008 a) that are best suited to meet the needs of the application (1004). For example, if the characteristics associated with the application (1004) indicate that the application (1004) requires a relatively low write latency and relatively high bandwidth, the subset of the resources within the single cloud-based storage system (1008 a) that may be selected (1102) to support the execution of the application (1004) can include the virtual drives within the cloud-based storage system that are supported by relatively powerful EC2 instances. Alternatively, if the characteristics associated with the application (1004) indicate that the application (1004) has flexibility with respect to the write latency and throughput, the subset of the resources within the single cloud-based storage system (1008 a) that may be selected (1102) to support the execution of the application (1004) can include the virtual drives within the cloud-based storage system that are supported by less powerful EC2 instances.

For further explanation, FIG. 12 sets forth a flow chart illustrating an example method of providing application-specific storage by a cloud-based storage system (1008 a, 1008 b, 1008 n) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 12 is similar to the example methods depicted in FIG. 10 and FIG. 11, as the example method depicted in FIG. 12 also includes identifying (1010), for an application (1004) that utilizes resources within the cloud-based storage system (1008 a, 1008 b, 1008 n), one or more characteristics associated with the application (1010) and selecting (1012), in dependence upon the one or more characteristics associated with the application (1004) and characteristics of resources (1016) within one or more cloud-based storage system (1008 a, 1008 b, 1008 n), one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004). Although not explicitly depicted in FIG. 12, at least a portion of a dataset associated with the application is stored as blocks within block storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n) and also stored as objects within object storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n).

The example method depicted in FIG. 12 also includes predicting (1202) a change to the application (1004). Predicting (1202) a change to the application (1004) may be carried out, for example, by performing a time-series analysis of various performance metrics associated with the application (1004) to identify trends associated with the application (1004), by examining telemetry data collected for similar applications to identify trends associated with the similar applications, or in some other way. As such, an examination of such information can be used to generate trending information for the applications (1004) including, for example, information describing the rate at which the number of IOPS being generated by the application (1004) has been changing, the rate at which overwrite rates for I/O operations that are being generated by the application (1004) are changing, the rate at which the amount of read bandwidth that is being consumed by I/O operations generated by the application (1004) is changing, and many others. In such a way, predicted characteristics of the application (1004) may be generated by extrapolating identified trends out over a period of time in the future.

Consider an example in which telemetry data gathered from a plurality of storage systems indicates that, on average, the amount of CPU resources required to support a virtual desktop infrastructure workload doubles every three years. In such an example, if a particular application (1004) is a virtual desktop infrastructure workload, predicting (1202) a change to the application (1004) may be carried out, at least in part, by determining the amount of CPU resources currently required to support the application (1004) and assuming that the amount of CPU resources that will be required to support the application (1004) in the future will double every three years. In such a way, the load demands created by each application (1004) may be projected to some point in the future.

The example method depicted in FIG. 12 also includes identifying (1206), in dependence upon the predicted change to the application (1004), one or more updated characteristics associated with the application (1004). Identifying (1206) one or more updated characteristics associated with the application (1004) may be carried out, for example, by utilizing trending information associated with the application (1004) itself, trending information associated with the application (1004) itself and trending information based on telemetry data associated with similar applications, or some combination thereof, to project how the application (1004) will operate in the future and to project what characteristics the application (1004) will exhibit in the future. Readers will appreciate that embodiments described herein may also leverage machine learning techniques to not only predicting (1202) a change to the application (1004) but also to identify (1206) one or more updated characteristics associated with the application (1004). In such an example, various metrics associated with the application (1004) and even similar applications may be fed into a machine learning model to detect the occurrence of changes to the application (1004), changes to the application's (1004) usage of underlying storage resources, and so on, to gain a better understanding of characteristics that the workload may take on in the future.

The example method depicted in FIG. 12 also includes detecting (1204) a change to the application (1004). Detecting (1204) a change to the application (1004) may be carried out, for example, by detecting a change to some configuration parameter associated with the application (1004), by detecting a change to the usage of the application (1004) (e.g., the number of users of a particular application has changed by a predetermined amount), by detecting that the application (1004) has begun exhibiting behavior that is outside of expected boundaries (e.g., the application has begun generating an amount of IOPS that are outside of an expected range), and in other ways. In response to detecting (1204) a change to the application (1004), the characteristics of the application (1004) may be reevaluated.

The example method depicted in FIG. 12 also includes identifying (1208), in dependence upon the detected change to the application (1004), one or more updated characteristics associated with the application (1004). Identifying (1208) one or more updated characteristics associated with the application (1004) may be carried out, for example, by performing the same analysis and actions described above with reference to at least step 1010 of FIG. 10, using the updated state of the application (1004) as input to such analysis. In such a way, the detection (1204) of a change to the application (1004) can essentially cause a management module or other appropriate actor to re-perform the analysis and actions to identify (1208) one or more updated characteristics associated with the application (1004).

The example method depicted in FIG. 12 also includes selecting (1210), in dependence upon the one or more updated characteristics associated with the application (1004) and characteristics of one or more resources within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n), an updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004). Selecting (1210) an updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) may be carried out, for example, by performing the same analysis and actions described above with reference to at least step 1012 of FIG. 10, using the one or more updated characteristics associated with the application (1004). In such a way, the identification (1208) of one or more updated characteristics associated with the application (1004) can essentially cause a management module or other appropriate actor to re-perform the analysis and actions to select (1210) an updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004).

In the example method depicted in FIG. 12, selecting (1210) an updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) can include modifying (1212) resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n). Modifying (1212) resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) may be carried out, for example, by creating new resources that are to be added to the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n). Consider an example in which an evaluation of the updated characteristics associated with the application (1004) indicated that an updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) that are needed to support the execution of the application (1004) would include additional capacity beyond the capacity that is offered by a particular cloud-based storage system (1008 a) that is currently supporting the execution of the application (1004). In such an example, modifying (1212) resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) may be carried out by adding additional virtual drives to the particular cloud-based storage system (1008 a) that is currently supporting the execution of the application (1004), by creating additional EC2 instances with local storage and adding the newly created EC2 instances with local storage to the pool of resources that are utilized by the storage system virtual controller compute instances.

In some embodiments, modifying (1212) resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) may be carried out, for example, by creating new resources that are to be used as replacements for existing resources within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n). Consider an example in which an evaluation of the updated characteristics associated with the application (1004) indicated that an updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) that are needed to support the execution of the application (1004) would include a more powerful cloud-computing instance that is needed to support the execution of the storage controller application than is currently offered by a particular cloud-based storage system (1008 a) that is supporting the execution of the application (1004). In such an example, modifying (1212) resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) may be carried out by creating a new, more powerful EC2 instance that is executing the storage controller application, configuring the new EC2 instance to utilize the storage resources that are included in the particular cloud-based storage system (1008 a) that is supporting the execution of the application (1004), and using the new EC2 instance to service I/O operations that are directed to the particular cloud-based storage system (1008 a) by the application (1004), while also terminating (or moving into a standby role) the EC2 instance that was previously servicing I/O operations that are directed to the particular cloud-based storage system (1008 a) by the application (1004). In such a way, modifying (1212) resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) can include modifying (1214) a storage controller layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n), where the storage controller layer includes each of the cloud-computing instances that are used to support the execution of the storage controller application. Readers will appreciate that modifying (1214) a storage controller layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n) can include creating additional cloud-computing instances that are used to support the execution of the storage controller application, terminating cloud-computing instances that are used to support the execution of the storage controller application, replacing a first cloud-computing instances that is used to support the execution of the storage controller application with a second cloud-computing instances that is used to support the execution of the storage controller application, and so on.

Readers will appreciate that although modifying (1214) a storage controller layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n) can be carried out by expanding or contracting the number of virtual storage system controller instances, modifying (1214) a storage controller layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n) can be carried out in other ways. For example, modifying (1214) a storage controller layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n) may be carried by upgrading or downgrading the performance and other characteristics of a particular virtual storage system controller instance, by replacing one or more virtual storage system controller compute instances with one or more virtual storage system controller compute instances with different performance and other characteristics, and in other ways.

Modifying (1212) resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) can also include modifying (1216) a virtual drive layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n), where the virtual drive layer includes the virtual drives in a particular cloud-based storage system (1008 a, 1008 b, 1008 n). Modifying (1216) a virtual drive layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n), where the virtual drive layer includes the virtual drives in a particular cloud-based storage system (1008 a, 1008 b, 1008 n) may be carried out, for example, by creating additional cloud computing instances with local storage to be used as virtual drives, by terminating cloud computing instances with local storage that were previously used as virtual drives, by replacing a first cloud computing instance with local storage that was used as a virtual drive with a second cloud computing instance with local storage that is to be used as a virtual drive, and so on. In such an example, it ultimately may be necessary to migrate data on a first virtual drive to a second virtual to more evenly distribute the portion of the dataset that is to be stored as blocks in block storage (thereby presumably more evenly distributing reads of the dataset).

Consider an example in which modifying (1216) a virtual drive layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n) includes adding X number of new virtual drives to a particular cloud-based storage system (1008 a). In such an example, the write bandwidth for the cloud-based storage system (1008 a) immediately increases as the X number of new virtual drives are available to service write operations. Without migrating the portions of the dataset that are stored in the already existing virtual drives, however, read bandwidth is not impacted much as only the already existing virtual drives are available for servicing read operations given that they are the only drives that include the dataset. By migrating at least some portions of the dataset that was stored on the already existing virtual drives to the X number of new virtual drives, both the X number of new virtual drives and the already existing drives may be available for servicing read operations as all of the virtual drives include at least some portion of the dataset. Readers will appreciate that some portion of the dataset that is stored on the already existing virtual drives to the X number of virtual drives may be migrated immediately upon the creation of the X number of new virtual drives, as resources are available to migrate data, according to some predetermined schedule, or in some other way (including not migrating data at all). Readers will appreciate that it also may be necessary to migrate data in response to other types of changes to the virtual drive layer.

Readers will appreciate that although modifying (1216) a virtual drive layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n) may be carried out to expand or contract the number of such virtual drive instances, thereby allowing an immediate change in write bandwidth, and allowing an eventual change in read bandwidth dependent on migrating data to rebalance the content, modifying (1216) a virtual drive layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n) could be carried out in other ways. For example, modifying (1216) a virtual drive layer in at least one of the cloud-based storage systems (1008 a, 1008 b, 1008 n) could be carried out by changing the configured performance of one or more virtual drives, changing networking resources that are used by the virtual drives and to access the virtual drives, by changing storage characteristics of individual virtual drive instances, and in other ways.

In the example method depicted in FIG. 12, after selecting (1210) an updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004) (including any associated modifications), the updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) are ultimately used to support the execution of the application (1004). In these embodiments, however, the application (1004) may utilize the updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) without migrating any portion of the dataset that is stored as objects within object storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n). As will be described in greater detail below, when additional virtual drives are added some pieces of the dataset that are stored as blocks in the block storage virtual drives may need to be migrated between virtual drives such that the dataset is distributed relatively evenly across the virtual drives. Such migration is not needed, however, for the portions of the dataset that are already stored as objects within object storage, as the object storage effectively has unlimited capacity, especially where the object storage is S3, and relatively steady read latencies regardless of where the data is actually located.

For further explanation, FIG. 13 sets forth a flow chart illustrating an example method of providing application-specific storage by a cloud-based storage system (1008 a, 1008 b, 1008 n) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 13 is similar to the example methods depicted in FIGS. 10-12, as the example method depicted in FIG. 13 also includes identifying (1010), for an application (1004) that utilizes resources within the cloud-based storage system (1008 a, 1008 b, 1008 n), one or more characteristics associated with the application (1010) and selecting (1012), in dependence upon the one or more characteristics associated with the application (1004) and characteristics of resources (1016) within one or more cloud-based storage system (1008 a, 1008 b, 1008 n), one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004). Although not explicitly depicted in FIG. 13, at least a portion of a dataset associated with the application is stored as blocks within block storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n) and also stored as objects within object storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n).

The example method depicted in FIG. 13 also includes detecting (1302) a change to one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n). Detecting (1302) a change to one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) may be carried out, for example, by detecting that one or more resources (e.g., one or more virtual drives, one or more storage system virtual controller compute instances) have failed or otherwise become unavailable, by detecting that one or more resources within a cloud-based storage system (1008 a, 1008 b, 1008 n) has become more/less available due to a change in usage of the cloud-based storage systems (1008 a, 1008 b, 1008 n), by detecting a change to the configuration of a cloud-based storage system (1008 a, 1008 b, 1008 n), or in some other way.

The example method depicted in FIG. 13 also includes identifying (1304), in dependence upon the detected change to one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n), one or more updated characteristics associated with the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n). Identifying (1304) one or more updated characteristics associated with the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) may be carried out, for example, by monitoring the performance of the cloud-based storage systems (1008 a, 1008 b, 1008 n), by extrapolating the one or more updated characteristics associated with the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) based on characteristics associated with the component parts of the cloud-based storage systems (1008 a, 1008 b, 1008 n), or in other ways. In such a way, the detection (1302) of a change to one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) can essentially cause a management module or other appropriate actor to re-perform the analysis and actions to identify (1304) one or more updated characteristics associated with the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n).

The example method depicted in FIG. 13 also includes selecting (1306), in dependence upon the characteristics associated with the application (1004) and the updated characteristics associated with the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n), an updated set of resources within the one or more cloud-based storage systems (1008 a, 1008 b, 1008 n) to support the execution of the application (1004). Selecting (804) one or more storage resources within the storage system (406) to support the execution of the application (404) may be carried out, for example, by comparing the one or more characteristics associated with the application (404) and the updated characteristics of storage resources within the storage system (406) to identify a best fit. In such an example, multiple aspects of the one or more characteristics associated with the application (404) and the updated characteristics of storage resources within the storage system (406) may be taken into consideration, in a weighted or unweighted fashion, to identify the set of storage resources that would provide the best fit for the application (404) given the updated characteristics of storage resources within the storage system (406).

For further explanation, FIG. 14 sets forth a flow chart illustrating an example method of providing application-specific storage by a cloud-based storage system (1008 a, 1008 b, 1008 n) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 14 is similar to the example methods depicted in FIGS. 10-13, as the example method depicted in FIG. 14 also includes identifying (1010), for an application (1004) that utilizes resources within the cloud-based storage system (1008 a, 1008 b, 1008 n), one or more characteristics associated with the application (1010) and selecting (1012), in dependence upon the one or more characteristics associated with the application (1004) and characteristics of resources (1016) within one or more cloud-based storage system (1008 a, 1008 b, 1008 n), one or more resources (1016) within the cloud-based storage system (1008 a, 1008 b, 1008 n) to support the execution of the application (1004). Although not explicitly depicted in FIG. 14, at least a portion of a dataset associated with the application is stored as blocks within block storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n) and also stored as objects within object storage resources in the cloud-based storage system (1008 a, 1008 b, 1008 n).

The example method depicted in FIG. 14 includes detecting (1402) that one or more resources (1016 a, 1016 b, 1016 n) within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) have become constrained. Detecting (1402) that one or more resources (1016 a, 1016 b, 1016 n) within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) have become constrained may be carried out, for example, by detecting that the utilization of a particular resource either has reached a predetermined utilization level (e.g., 90% of full utilization). Consider an example in which multiple applications are supported by the same resources (e.g., the same virtual controllers, the same virtual drives). In such an example, the extent to which one application consumes resources can impact the extent to which another application has access to system resources. For example, if a first application begins generating very large amount of I/O operations, a second application may experience a delay in having its I/O operations serviced as each application may route its I/O operations through the same set of virtual controllers. In such an example, detecting (1402) that one or more resources (1016 a, 1016 b, 1016 n) within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) have become constrained may be carried out, for example, by detecting that the utilization of the virtual controllers has reached the predetermined utilization level.

The example method depicted in FIG. 14 also includes automatically (1404), without user intervention, performing corrective actions. In the example method depicted in FIG. 14, the corrective actions may take a variety of forms. For example, automatically (1404) performing corrective actions may include, adding additional resources to a particular cloud-based storage system (1008 a, 1008 b, 1008 n), replacing less powerful resources in the cloud-based storage system (1008 a, 1008 b, 1008 n) with more powerful resources, and so on. Consider an example in which the virtual controllers for a particular cloud-based storage system (1008 a) are becoming constrained. In such an example, automatically (1404) performing corrective actions may be carried out, for example, by creating additional virtual controllers and configuring one or more applications that were utilizing the over-constrained virtual controller to use the newly created virtual controller. Readers will appreciate that other modifications to one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) described above may also be performed automatically as part of automatically (1404) performing corrective actions.

As another example of automatically (1404) performing corrective actions, applications may be reconfigured to utilize different, less utilized resources within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n). Readers will appreciate that, as described above, such a reconfiguration may occur without migrating data that is already stored as objects within object storage resources. Readers will further appreciate that although FIG. 14 relates to an embodiment that detects (1402) that one or more resources (1016 a, 1016 b, 1016 n) within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) have become constrained, in some embodiment, such a detection may be preemptive such that corrective actions are taken in response to detecting (1402) that one or more resources (1016 a, 1016 b, 1016 n) within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) will become constrained.

The example method depicted in FIG. 14 also includes receiving (1406), via a storage tuning interface (an example of which is depicted in FIG. 15 and described below), tuning information for a cloud-based storage system (1008 a, 1008 b, 1008 n) that is utilized by the application (1404). Such tuning information can include information describing, for example, the amount of storage performance a user would like to be available to the application (1404). The storage performance may include, for example, the amount of IOPS that the storage should be able to service, the read latency that the storage should be able to provide, the write latency that the storage should be able to provide, and so on. Likewise, tuning information can include information describing the amount and type of capacity that should be provided to the application (1404). In addition, the tuning information can include other types of tuning information as described below with reference to FIG. 15. In response to receiving (1406) tuning information, resources within one or more of the cloud-based storage systems (1008 a, 1008 b, 1008 n) may be modified (1212 in FIG. 12) as described above with reference at least to FIG. 12.

For further explanation, FIG. 15 sets forth a graphical user interface (‘GUI’) (1502) for tuning storage according to some embodiments of the present disclosure. The GUI (1502) depicted in FIG. 15 includes tunable knobs (1504, 1506, 1508, 1510) that enable a user of the GUI (1502) to tune the storage that is provided a particular application. In the example GUI (1502) depicted in FIG. 15, a user of the GUI (1502) may tune storage for a particular application that is selected from an application selection dropdown menu (1512), although in other embodiments the GUI (1502) could utilize other mechanisms for selecting a particular application, including selecting the particular application prior to launching an instance of the GUI. In such a way, storage may be tuned on a per-application basis, meaning that storage may be tuned in one way for a first application and tuned in another way for second application.

The example GUI (1502) depicted in FIG. 15 includes four knobs:

-   -   a. A performance knob (1504) that enables a user to select the         amount of storage performance that the user would like to be         available to the application. The storage performance may         include, for example, the amount of IOPS that the storage should         be able to service, the read latency that the storage should be         able to provide, the write latency that the storage should be         able to provide, and so on. In such an example, the user may be         able to view the various performance metrics that can be         delivered at each value on the performance knob (1504) in a         variety of ways. For example, hovering a mouse pointer over a         particular value (e.g., ‘6’) on the service knob (1504) may         cause a pop-up to be generated that identifies the number of         IOPS that the storage will perform at that value on the service         knob (1504), a read latency that the storage will deliver at         that value on the service knob (1504), and so on. Alternatively,         a second window may exist to display the various performance         metrics that can be delivered at the currently selected value on         the performance knob (1504). Readers will appreciate that a         secondary window, pop-up, or other medium for conveying         information to the user can include additional information,         including the costs associated with a particular value on the         performance knob (1504).     -   b. A recovery knob (1506) that enables a user to select how         available the storage is to a particular application. In such an         example, a particular recovery value on the recovery knob (1506)         may be associated with a particular availability guarantee         (e.g., the storage is guaranteed to be available 99.9999% of the         time), a particular recovery value on the recovery knob (1506)         may be associated with a particular recovery time objective         (‘RTO’) that specifies how long it will take the storage to         restore from an incident that causes the storage to become         unavailable, a particular recovery value on the recovery knob         (1506) may be associated with a particular recovery point         objective (‘RPO’) that limits how far the storage can be rolled         back in time after a failure incident and defines the maximum         allowable amount of lost data measured in time from a failure         occurrence to the last valid backup, and so on. In such an         example, the user may be able to view the various         recovery-related metrics and guarantees that can be delivered at         each value on the recovery knob (1506) in a variety of ways. For         example, hovering a mouse pointer over a particular value (e.g.,         ‘6’) on the recovery knob (1506) may cause a pop-up to be         generated that contains information describing the various         recovery-related metrics and guarantees that can be delivered at         that particular value. Alternatively, a second window may exist         to display information describing the various recovery-related         metrics and guarantees that can be delivered at the currently         selected value on the recovery knob (1506). Readers will         appreciate that a secondary window, pop-up, or other medium for         conveying information to the user can include additional         information, including the costs associated with a particular         value on the recovery knob (1506).     -   c. A security knob (1508) that enables a user to select how         secure that data associated with a particular application should         be. In such an example, a particular value on the security knob         (1508) can be associated with how heavily the storage should         encrypt data that is associated with a particular application, a         particular value on the security knob (1508) can be associated         with a particular encryption algorithm that the storage should         encrypt data that is associated with a particular application, a         particular value on the security knob (1508) can be associated         with the extent to which data that is associated with a         particular application should be stored in a way that is General         Data Protection Regulation (‘GDPR’) compliant, and so on. In         such an example, the user may be able to view the various         security-related guarantees that can be delivered at each value         on the security knob (1508) in a variety of ways. For example,         hovering a mouse pointer over a particular value (e.g., ‘6’) on         the security knob (1508) may cause a pop-up to be generated that         contains information describing the various security-related         guarantees that can be delivered at that particular value on the         security knob (1508). Alternatively, a second window may exist         to display information describing the various security-related         guarantees that can be delivered at the currently selected value         on the security knob (1508). Readers will appreciate that a         secondary window, pop-up, or other medium for conveying         information to the user can include additional information,         including the costs associated with a particular value on the         security knob (1508).     -   d. A location knob (1510) that enables a user to select where         data associated with a particular application should be kept. In         such an example, a particular value on the location knob (1510)         can be associated with a requirement that data that is         associated with a particular application should be kept within a         predefined proximity (e.g., on the same network) relative to the         location where the application is executing, a particular value         on the location knob (1510) can be associated with a requirement         that data that is associated with a particular application         should be kept on a location that meets certain predefined         criteria (e.g., behind a firewall, on a non-public cloud, on a         public cloud), and so on. In such an example, the user may be         able to view the various location-related guarantees that can be         delivered at each value on the location knob (1510) in a variety         of ways. For example, hovering a mouse pointer over a particular         value (e.g., ‘6’) on the location knob (1510) may cause a pop-up         to be generated that contains information describing the various         location-related guarantees that can be delivered at that         particular value on the location knob (1510). Alternatively, a         second window may exist to display information describing the         various location-related guarantees that can be delivered at the         currently selected value on the location knob (1510). Readers         will appreciate that a secondary window, pop-up, or other medium         for conveying information to the user can include additional         information, including the costs associated with a particular         value on the location knob (1510).

Readers will appreciate that the GUI (1502) depicted in FIG. 15 in only one example of a GUI that may be provided in accordance with embodiments of the present disclosure. In other embodiments, such a GUI can include additional or fewer knobs that relate to additional or fewer characteristics of storage that is to be provided to a particular application. For example, one additional knob that may be of particular interest when tuning cloud-based storage systems is a ‘cost’ knob. Readers will appreciate that in constructing a cloud-based storage system, some of the underlying resources (e.g., EC2 instances that support the execution of the storage controller application, EC2 instances with local storage that can be used as virtual drives, S3 buckets, networking resources used to support communications between various components, and many other) may be billed based on usage. For example, Amazon may charge for the usage of such resources in AWS, Microsoft may charge for the usage of such resources in Azure, and so on. As such, a ‘cost’ knob may be used to specify the extent to which cost considerations should be taken into consideration. For example, if the ‘cost’ knob is set to a value such that controlling costs is critical, steps may be taken to control costs. Examples of steps that may be taken to control costs can include, for example, executing the storage controller application on a relatively low-powered (i.e., cheap) EC2 instance type, having only a single EC2 instance that is executing the storage controller application thereby increasing the amount of time that is required to fail over to a new EC2 instance, having the dataset only partially mirrored in the virtual drive layer rather than having the entire dataset available in the virtual drive layer, and so on. Alternatively, if the ‘cost’ knob is set to a value such that controlling costs is not important, steps may be taken to guarantee higher levels of performance, durability, and the like—regardless of the associated financial costs.

Readers will further appreciate that such GUIs enable a user to select various characteristics of storage that should be made accessible to a particular application, while the implementation details associated with providing such storage are handled automatically and without user intervention. In such an example, storage systems such as those described above may provide the actual storage to the application. The storage systems may reside, for example, in a data center, in a cloud computing environment as described above, or other location and may include storage systems that provide block storage, storage systems that provide file storage, storage systems that provide object storage, or any combination thereof. Furthermore, the storage systems may be scale-up storage systems, scale-out storage systems, or any combination thereof. In such an example, the user's manipulation of the GUI may cause the application to be moved within the data center in order to obtain the desired characteristics of the storage that is accessible to the application, the application may mount a volume that is given sufficient resources to deliver the desired characteristics of the storage that is accessible to the application, a replication policy or backup policy may be attached to a volume that is used as storage for a particular application in order to achieve backup or availability objectives for the storage that is accessible to the application, and so on. Stated more generally, the application, storage system, networking resources, storage resources, or other resources may be configured in response to a user's manipulation of the GUI in order to provide storage to the application in accordance with the desired storage characteristics as expressed via the GUI.

In some embodiments of the present disclosure, an infrastructure discovery service may be utilized to determine the particular capabilities and resources that are offered by a particular system, such as one of the storage systems described above. Such an infrastructure discovery service may be embodied, for example, as one or more modules of computer program instructions that are executing on computer hardware, including virtualized execution environments such as a virtual machine, a container, and so on. The infrastructure discovery service may be configured to take an inventory of a particular system to discover the hardware components contained therein, the software components contained therein, the networking components contained therein, and so on. In such a way, the infrastructure discovery service can detect what resources and capabilities that a particular system can provide, such that a preliminary determination can be made as to whether a particular system has the necessary resources to support a particular application in accordance with its characteristics.

For further explanation, FIG. 16 sets forth a flow chart illustrating an example method of providing highly available application-specific storage by a cloud-based storage system (1618 a, 1618 b, 1618 n) in accordance with some embodiments of the present disclosure. The example method depicted in FIG. 16 includes a host (1602), an application (1604) that is executing on the host (1602), a cloud computing environment (1606), and cloud-based storage systems (1618 a, 1618 b, 1618 n) that may be similar to those described above. The cloud-based storage systems (1618 a, 1618 b, 1618 n) illustrated in FIG. 16 each include one or more components (1620 a, 1620 b, 1620 n) that may be embodied, for example, as virtual drives, cloud-computing instances that are supporting the execution of one or more applications such as a storage controller application, one or more pools of object storage, one or more polls of block storage, and any of the other components that are depicted as being included in a cloud-based storage system as described above including combinations thereof. In the example method depicted in FIG. 16, at least a portion of a dataset that is associated with the application (1604) is stored as blocks within block storage resources in the cloud-based storage system (1618 a, 1618 b, 1618 n) and also stored as objects within object storage resources in the cloud-based storage system (1618 a, 1618 b, 1618 n), as described in greater detail above.

The example method depicted in FIG. 16 includes detecting (1608) that a component (1620 a, 1620 b, 1620 n) within a cloud-based storage system (1618 a, 1618 b, 1618 n) that supports an application (1604) has become unavailable. Readers will appreciate that a component (1620 a, 1620 b, 1620 n) within a cloud-based storage system (1618 a, 1618 b, 1618 n) may become unavailable, for example, in response to some underlying resource within the cloud computing environment (1606) failing or otherwise becoming unavailable. For example, a cloud computing instance or virtual machine that supports the execution of a storage controller application may fail, thereby causing the virtual storage controller to become unavailable. Likewise, or more EBS volumes, an Azure managed disk instance, or some other storage offering provided by a cloud services provider may fail such that some storage component in the cloud-based storage system (1618 a, 1618 b, 1618 n) also fails. In such an example, detecting (1608) that a component (1620 a, 1620 b, 1620 n) within a cloud-based storage system (1618 a, 1618 b, 1618 n) that supports an application (1604) has become unavailable may be carried out by periodically checking the health of an underlying cloud resource, by receiving a notification that some underlying cloud resource has failed, or in many other ways.

The example method depicted in FIG. 16 also includes selecting (1610) a replacement component within the cloud-based storage system (1618 a, 1618 b, 1618 n) to support the application (1604). Selecting (1610) a replacement component within the cloud-based storage system (1618 a, 1618 b, 1618 n) may be carried out, for example, by creating (1614) the replacement component in situations where a viable replacement component is not already created. Readers will appreciate that creating (1614) the replacement component can be carried out relatively quickly by spinning up new instances of cloud resources that are needed to form the component. Alternatively, selecting (1610) a replacement component within the cloud-based storage system (1618 a, 1618 b, 1618 n) to support the application (1604) could be carried out by selecting (1616) a mirrored copy of the component that has become unavailable. Such a mirrored copy of the component that has become unavailable may be embodied, for example, as a copy of the component that has become unavailable that resides with another availability zone, as a copy of the component that has become unavailable that was created as a standby replacement component, and so on. In such an example, configuration information associated with the cloud-based storage system may be updated to replace the component that has become unavailable with the replacement component, networking information may be updated to incorporate the replacement component into the cloud-based storage system and to remove the component that has become unavailable from the cloud-based storage system, and other steps may be performed to fully integrate the replacement component into the cloud-based storage system.

As mentioned above, in some embodiments the component that has become unavailable may be embodied as a cloud computing instance that supports the execution of a storage controller application. In such an example, selecting (1610) a replacement component within the cloud-based storage system (1618 a, 1618 b, 1618 n) to support the application (1604) can therefore include executing (1612) the storage controller application on a replacement cloud computing instance. The replacement cloud computing instance may be embodied, for example, as an EC2 instance in Amazon's AWS™, as an Azure Virtual Machine, as container resources that are offered by a cloud services provider, or in some other way. In such an example, the cloud computing instance that has become unavailable may be located within a first geographical zone and the replacement cloud computing instance may be located within a second geographical zone. Such geographical zones may be embodied, for example, as distinct availability zones in Amazon's AWS™, as distinct availability regions in Microsoft's Azure, or in some other way such that a failure in a first geographical zone would not cause a failure in a second geographical zone. In such a way, especially where mirrored copies of components are created in different geographical zones, the overall cloud-based storage system would be more highly available as both components failing at the same time would be less likely than if the components resided within the same geographical zone.

Although some example embodiments are described in a way where a series of steps appear to be occurring in a particular order, no such ordering is required unless explicitly stated. Likewise, steps that are depicted in one figure may be combined with steps described in another figure, even if the respective steps are not depicted in a single figure. Readers will further appreciate that although various embodiments may be described separately from each other, combinations of multiple embodiments are also within the scope of the present disclosure unless explicitly prohibited.

In view of the descriptions contained above, embodiments described herein can provide for many benefits, including at least the following:

-   -   Applications can be supported by storage systems that are         intelligently tailored to supply the appropriate level of         support to the application.     -   Storage resources can be efficiently utilized to avoid wasting         resources, oversubscribing resources, and the like.

Example embodiments are described largely in the context of a fully functional computer system. Readers of skill in the art will recognize, however, that the present disclosure also may be embodied in a computer program product disposed upon computer readable storage media for use with any suitable data processing system. Such computer readable storage media may be any storage medium for machine-readable information, including magnetic media, optical media, or other suitable media. Examples of such media include magnetic disks in hard drives or diskettes, compact disks for optical drives, magnetic tape, and others as will occur to those of skill in the art. Persons skilled in the art will immediately recognize that any computer system having suitable programming means will be capable of executing the steps of the method as embodied in a computer program product. Persons skilled in the art will recognize also that, although some of the example embodiments described in this specification are oriented to software installed and executing on computer hardware, nevertheless, alternative embodiments implemented as firmware or as hardware are well within the scope of the present disclosure.

Embodiments can include be a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present disclosure.

The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.

Computer readable program instructions for carrying out operations of the present disclosure may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure.

Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to some embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.

These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.

The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 

What is claimed is:
 1. A method comprising: monitoring execution of an application that is supported by a cloud-based storage system; identifying one or more performance characteristics of the application during the monitoring of the application; detecting that a virtualized component within a cloud-based storage system that supports an application has become unavailable; and selecting, based on the one or more performance characteristics of the application identified during execution and performance characteristics of resources within one or more cloud-based storage systems, a particular storage subsystem to execute a replacement virtualized component within the cloud-based storage system to support the application, wherein at least a portion of a dataset associated with the application is stored as blocks within block storage resources in the cloud-based storage system and also stored as objects within object storage resources in the cloud-based storage system.
 2. The method of claim 1 wherein: the virtualized component that has become unavailable is a cloud computing instance that supports the execution of a storage controller application; and selecting a particular storage subsystem to execute a replacement virtualized component within the cloud-based storage system to support the application further comprises executing the storage controller application on a replacement cloud computing instance.
 3. The method of claim 2 wherein: the cloud computing instance is located within a first geographical zone; and the replacement cloud computing instance is located within a second geographical zone.
 4. The method of claim 1 wherein selecting the particular storage subsystem to execute the replacement virtualized component within the cloud-based storage system to support the application further comprises creating a cloud computing instance executing the replacement virtualized component.
 5. The method of claim 1 wherein selecting the particular storage subsystem to execute the replacement virtualized component within the cloud-based storage system further comprises selecting a mirrored copy of the virtual component that has become unavailable.
 6. The method of claim 1 wherein: the virtual component that has become unavailable is located within a first geographical zone; and the replacement virtualized component is located within a second geographical zone.
 7. An apparatus comprising a computer processor, a computer memory operatively coupled to the computer processor, the computer memory having disposed within it computer program instructions that, when executed by the storage system, cause the apparatus to carry out the steps of: monitoring execution of an application that is supported by a cloud-based storage system; identifying one or more performance characteristics of the application during the monitoring of the application; detecting that a virtualized component within a cloud-based storage system that supports an application has become unavailable; and selecting, based on the one or more performance characteristics of the application identified during execution and performance characteristics of resources within one or more cloud-based storage systems, a particular storage subsystem to execute a replacement virtualized component within the cloud-based storage system to support the application, wherein at least a portion of a dataset associated with the application is stored as blocks within block storage resources in the cloud-based storage system and also stored as objects within object storage resources in the cloud-based storage system.
 8. The apparatus of claim 7 wherein: the virtual component that has become unavailable is a cloud computing instance that supports the execution of a storage controller application; and selecting a particular storage subsystem to execute a replacement virtualized component within the cloud-based storage system to support the application further comprises executing the storage controller application on a replacement cloud computing instance.
 9. The apparatus of claim 8 wherein: the cloud computing instance is located within a first geographical zone; and the replacement cloud computing instance is located within a second geographical zone.
 10. The apparatus of claim 7 wherein selecting the replacement virtualized component within the cloud-based storage system to support the application further comprises creating the replacement virtualized component.
 11. The apparatus of claim 7 wherein selecting the replacement virtualized component within the cloud-based storage system further comprises selecting a mirrored copy of the virtual component that has become unavailable.
 12. The apparatus of claim 7 wherein: the virtual component that has become unavailable is located within a first geographical zone; and the replacement virtualized component is located within a second geographical zone.
 13. A computer program product disposed on a non-transitory computer readable medium, the computer program product including computer program instructions that, when executed, carry out the steps of: monitoring execution of an application that is supported by a cloud-based storage system; identifying one or more performance characteristics of the application during the monitoring of the application; detecting that a virtualized component within a cloud-based storage system that supports an application has become unavailable; and selecting, based on the one or more performance characteristics of the application identified during execution and performance characteristics of resources within one or more cloud-based storage systems, a replacement virtualized component within the cloud-based storage system to support the application, wherein at least a portion of a dataset associated with the application is stored as blocks within block storage resources in the cloud-based storage system and also stored as objects within object storage resources in the cloud-based storage system.
 14. The computer program product of claim 13 wherein: the virtual component that has become unavailable is a cloud computing instance that supports the execution of a storage controller application; and selecting a replacement virtualized component within the cloud-based storage system to support the application further comprises executing the storage controller application on a replacement cloud computing instance.
 15. The computer program product of claim 14 wherein: the cloud computing instance is located within a first geographical zone; and the replacement cloud computing instance is located within a second geographical zone.
 16. The computer program product of claim 13 wherein selecting the replacement virtualized component within the cloud-based storage system to support the application further comprises creating the replacement virtualized component.
 17. The computer program product of claim 13 wherein selecting the replacement virtualized component within the cloud-based storage system further comprises selecting a mirrored copy of the virtual component that has become unavailable.
 18. The computer program product of claim 13 wherein: the virtual component that has become unavailable is located within a first geographical zone; and the replacement virtualized component is located within a second geographical zone.
 19. The computer program product of claim 13 further comprising computer program instructions that, when executed, carry out the steps of: identifying, for an application that utilizes resources within the cloud-based storage system, one or more performance characteristics associated with the application; and selecting, in dependence upon the one or more performance characteristics associated with the application and performance characteristics of resources within one or more cloud-based storage systems.
 20. The computer program product of claim 19 wherein selecting, in dependence upon the one or more performance characteristics associated with the application and performance characteristics of resources within one or more cloud-based storage systems, one or more resources within the one or more cloud-based storage systems to support the execution of the application further comprises selecting, from available resources that could be included in a cloud-based storage system, a subset of resources that can be provided by the cloud computing environment for inclusion within the cloud-based storage system that is to be created to support the execution of the application. 